# DevBento - Developer Tools

> Free, privacy focused developer tools that run entirely in your browser.

## Tools

- [Base64 Encode/Decode](https://devbento.dev/tools/base64-encoder): Encode text to Base64 or decode Base64 strings. Supports UTF-8 and binary data.
- [UUID Generator](https://devbento.dev/tools/uuid-generator): Generate UUID v4 (random) and v7 (time ordered). Bulk generation up to 1000.
- [Unix Timestamp Converter](https://devbento.dev/tools/unix-timestamp): Convert Unix timestamps to dates and vice versa. Live clock, timezone support.
- [JSON Formatter + Tree Viewer](https://devbento.dev/tools/json-formatter): Format, minify, or validate JSON with syntax highlighting and tree view.
- [Token Counter + LLM Cost Calculator](https://devbento.dev/tools/token-counter): Count tokens for GPT-4o, Claude, Gemini. Estimate API costs with tiktoken.
- [Diff Checker](https://devbento.dev/tools/diff-checker): Compare text side by side or inline with character level highlighting.
- [JWT Decoder](https://devbento.dev/tools/jwt-decoder): Decode and inspect JWT tokens. View header, payload claims, and expiration status.
- [JWT Generator](https://devbento.dev/tools/jwt-generator): Generate signed JWT tokens for testing. HS256 and RS256 signing with configurable standard and custom claims.
- [URL Encoder & HTML Entity Encoder](https://devbento.dev/tools/url-encoder): Encode URLs (encodeURIComponent/encodeURI) and escape HTML entities.
- [Hash Generator](https://devbento.dev/tools/hash-generator): Generate MD5, SHA-1, SHA-256, SHA-512 hashes from text or files. Uses Web Crypto API.
- [Cron Expression Builder](https://devbento.dev/tools/cron-builder): Build cron expressions interactively. Plain English explanation and next 5 run times.
- [Regex Tester](https://devbento.dev/tools/regex-tester): Test regex patterns with live match highlighting, capture groups, and common presets.
- [SQL / CSS / HTML Formatter](https://devbento.dev/tools/code-formatter): Format and minify SQL queries, CSS stylesheets, and HTML markup with syntax highlighting.
- [Color Converter](https://devbento.dev/tools/color-converter): Convert colors between HEX, RGB, HSL, and named formats. Generate palettes.
- [CSS Gradient Generator](https://devbento.dev/tools/css-gradient): Create linear, radial, and conic CSS gradients visually. Drag color stops, adjust angles, copy CSS.
- [Data Converter](https://devbento.dev/tools/data-converter): Convert between JSON, YAML, CSV, and TOML formats.
- [.gitignore Generator](https://devbento.dev/tools/gitignore-generator): Generate .gitignore files from 30+ templates. Select languages, editors, OS. Download or copy.
- [HTTP Status Code Reference](https://devbento.dev/tools/http-status-codes): Look up every HTTP status code from 100 to 511. Searchable with category filters and plain English explanations.
- [Markdown Preview](https://devbento.dev/tools/markdown-preview): Render Markdown to HTML in real time with GFM tables, task lists, and code blocks. Copy generated HTML.
- [Password Generator](https://devbento.dev/tools/password-generator): Generate cryptographically secure random passwords with customizable length and character sets.
- [QR Code Generator](https://devbento.dev/tools/qr-code): Generate QR codes from text or URLs. Customize size, error correction, and colors.
- [Image Format Converter](https://devbento.dev/tools/image-converter): Convert images between PNG, JPG, WebP, HEIC, SVG, GIF, BMP, ICO. Resize, compress, batch convert. No upload.
- [Background Remover](https://devbento.dev/tools/background-remover): Remove backgrounds from images with AI. Runs entirely in your browser using WebAssembly. No upload, no account.
- [Passport Photo Maker](https://devbento.dev/tools/passport-photo): Create compliant passport photos for US, UK, EU, Canada, India, China, Australia, Japan. AI background removal, official dimensions, print-ready sheets.
- [Mermaid Diagram Editor](https://devbento.dev/tools/mermaid-editor): Create flowcharts, sequence diagrams, ER diagrams, and more with live Mermaid preview. Export as SVG or PNG.
- [Unit Converter](https://devbento.dev/tools/unit-converter): Convert between length, weight, temperature, speed, area, volume, data, and time units. 60+ units, instant results.
- [Timezone Converter](https://devbento.dev/tools/timezone-converter): Compare time across multiple IANA timezones. DST aware, add/remove targets, live clock, shareable permalinks.
- [Random String / API Key Generator](https://devbento.dev/tools/random-string-generator): Generate random strings, API keys, and tokens with custom character sets, prefixes, suffixes, and grouping.
- [CSS Units Converter](https://devbento.dev/tools/css-units-converter): Convert between CSS units: px, rem, em, vw, vh, pt, cm, mm, in. Context-aware with configurable base font size and viewport dimensions.
- [Color Palette from Image](https://devbento.dev/tools/color-palette): Extract dominant colors from any image. Upload a photo, logo, or screenshot and get instant color swatches with hex codes, RGB values, and population percentages. Median cut quantization. Export as CSS variables or JSON.

## Examples — Timezone Converter

- [Convert EST to PST](https://devbento.dev/tools/timezone-converter/est-to-pst): Eastern to Pacific time conversion. 3 hour difference with DST handling.
- [Convert UTC to IST](https://devbento.dev/tools/timezone-converter/utc-to-ist): UTC to India Standard Time. Constant UTC+5:30 offset, no DST, remote dev team scheduling.

## Examples — Text Statistics

- [Word Count for an Essay](https://devbento.dev/tools/text-statistics/count/essay): Count words, characters, and reading time in a 500-word sample essay. Check academic writing limits and sentence structure.
- [Readability Check for a Blog Post](https://devbento.dev/tools/text-statistics/check/readability): Analyze Flesch Reading Ease of a sample blog post. See word frequency, longest sentences, and optimization tips.
- [Character Count for Social Media](https://devbento.dev/tools/text-statistics/count/social-media): Check character count against Twitter, LinkedIn, and Instagram limits. See reading time and platform-specific tips.

## Examples — Unit Converter

- [Celsius to Fahrenheit Converter](https://devbento.dev/tools/unit-converter/celsius-to-fahrenheit): Convert Celsius to Fahrenheit. Formula, common temperature references, head estimation trick.
- [Fahrenheit to Celsius Converter](https://devbento.dev/tools/unit-converter/fahrenheit-to-celsius): Convert Fahrenheit to Celsius. Formula, body temperature reference, quick estimate method.
- [Kg to Lbs Converter](https://devbento.dev/tools/unit-converter/kg-to-lbs): Convert kilograms to pounds. Conversion table, formula, stone equivalent.
- [Lbs to Kg Converter](https://devbento.dev/tools/unit-converter/lbs-to-kg): Convert pounds to kilograms. Conversion table, formula, quick mental math.
- [Miles to Km Converter](https://devbento.dev/tools/unit-converter/miles-to-km): Convert miles to kilometers. Marathon distance, running references, quick estimate.
- [Meters to Feet Converter](https://devbento.dev/tools/unit-converter/meters-to-feet): Convert meters to feet. Height conversion table, feet and inches breakdown.
- [Liters to Gallons Converter](https://devbento.dev/tools/unit-converter/liters-to-gallons): Convert liters to US gallons. Fuel references, cooking volumes, US vs UK difference.
- [Inches to Centimeters Converter](https://devbento.dev/tools/unit-converter/inches-to-centimeters): Convert inches to centimeters. Exact 2.54 factor, height conversion examples.
- [MPH to KPH Converter](https://devbento.dev/tools/unit-converter/mph-to-kph): Convert miles per hour to kilometers per hour. Speed limit references for driving.

## Examples — Image Format Converters

- [PNG to JPG Converter](https://devbento.dev/tools/convert/png-to-jpg): Convert PNG images to JPEG. Quality slider, transparency handling.
- [JPG to PNG Converter](https://devbento.dev/tools/convert/jpg-to-png): Convert JPEG to lossless PNG. No further quality loss during editing.
- [PNG to WebP Converter](https://devbento.dev/tools/convert/png-to-webp): Convert PNG to WebP for 40-60% smaller files with transparency support.
- [JPG to WebP Converter](https://devbento.dev/tools/convert/jpg-to-webp): Convert JPEG to WebP. 25-35% smaller at equivalent visual quality.
- [WebP to PNG Converter](https://devbento.dev/tools/convert/webp-to-png): Convert WebP to PNG for compatibility with tools that don't support WebP.
- [WebP to JPG Converter](https://devbento.dev/tools/convert/webp-to-jpg): Convert WebP to JPEG for universal compatibility.
- [HEIC to JPG Converter](https://devbento.dev/tools/convert/heic-to-jpg): Convert iPhone HEIC photos to JPEG. Client-side WASM decoding.
- [HEIC to PNG Converter](https://devbento.dev/tools/convert/heic-to-png): Convert iPhone HEIC photos to lossless PNG.
- [HEIC to WebP Converter](https://devbento.dev/tools/convert/heic-to-webp): Convert iPhone HEIC photos to WebP.
- [PNG to AVIF Converter](https://devbento.dev/tools/convert/png-to-avif): Convert PNG to AVIF for 50-90% smaller files. Supports transparency.
- [JPG to AVIF Converter](https://devbento.dev/tools/convert/jpg-to-avif): Convert JPEG to AVIF. 30-50% smaller at equivalent visual quality.
- [WebP to AVIF Converter](https://devbento.dev/tools/convert/webp-to-avif): Convert WebP to AVIF. Next-generation format with 20-30% better compression.
- [SVG to PNG Converter](https://devbento.dev/tools/convert/svg-to-png): Rasterize SVG vector images to PNG at any resolution.
- [BMP to JPG Converter](https://devbento.dev/tools/convert/bmp-to-jpg): Convert uncompressed BMP to JPEG. 90%+ size reduction.
- [BMP to PNG Converter](https://devbento.dev/tools/convert/bmp-to-png): Convert BMP to lossless PNG compression.
- [GIF to PNG Converter](https://devbento.dev/tools/convert/gif-to-png): Extract first frame of GIF as PNG. Full color depth.
- [ICO to PNG Converter](https://devbento.dev/tools/convert/ico-to-png): Extract PNG from ICO favicon files.
- [Favicon Generator](https://devbento.dev/tools/convert/favicon-generator): Generate multi-size ICO favicon from any image. Packs 16x16, 32x32, 48x48 into one file.
- [Resize Image Online](https://devbento.dev/tools/convert/resize-image): Resize images by pixels or percentage. Aspect ratio lock, preset dimensions.
- [Compress Image Online](https://devbento.dev/tools/convert/compress-image): Reduce image file size with quality control. WebP and JPEG compression.
- [Rotate Image Online](https://devbento.dev/tools/convert/rotate-image): Rotate images 90, 180, 270 degrees. Flip horizontally or vertically. Live preview.
- [Flip Image Online](https://devbento.dev/tools/convert/flip-image): Mirror images horizontally or vertically. Fix selfies, correct scans. Live preview.
- [PNG to SVG Converter: Trace Images to Vector Online](https://devbento.dev/tools/image-converter/png-to-svg): Convert PNG images to scalable SVG vectors using Potrace. Adjust threshold and detail for optimal results. Client-side, no upload needed.
- [Image to SVG Converter: Trace Any Image to Vector](https://devbento.dev/tools/image-converter/image-to-svg): Convert any image (PNG, JPG, WebP) to scalable SVG vectors. Adjust threshold, detail, and color settings. Client-side processing.

## Examples — Cron Schedules

- [Cron Every Minute — * * * * *](https://devbento.dev/tools/cron/every-minute): Run a cron job every minute. Covers flock, subminute alternatives.
- [Cron Every 5 Minutes — */5 * * * *](https://devbento.dev/tools/cron/every-5-minutes): Step operator explained. 12 runs/hour for health checks and cache refresh.
- [Cron Every 10 Minutes — */10 * * * *](https://devbento.dev/tools/cron/every-10-minutes): 6 runs/hour. Offset syntax for staggering multiple jobs.
- [Cron Every 15 Minutes — */15 * * * *](https://devbento.dev/tools/cron/every-15-minutes): Quarter hour intervals. 96 runs/day, the goldilocks default.
- [Cron Every 30 Minutes — */30 * * * *](https://devbento.dev/tools/cron/every-30-minutes): Twice per hour schedule. */30 vs 0,30 syntax and phase shifting.
- [Cron Every Hour — 0 * * * *](https://devbento.dev/tools/cron/every-hour): Hourly jobs. The @hourly shorthand and staggering tips.
- [Cron Daily at Midnight — 0 0 * * *](https://devbento.dev/tools/cron/daily-at-midnight): Daily schedule. Timezone pitfalls, DST edge cases, @daily alias.
- [Cron Weekdays at 9 AM — 0 9 * * 1-5](https://devbento.dev/tools/cron/weekdays-at-9am): Monday through Friday at 9 AM. Day of week numbering and business hours patterns.
- [Cron Every Weekday — 0 0 * * 1-5](https://devbento.dev/tools/cron/every-weekday): Weekday only scheduling. MON through FRI aliases, holiday workarounds.
- [Cron Every Monday — 0 0 * * 1](https://devbento.dev/tools/cron/every-monday): Weekly Monday jobs. Day numbering (Monday = 1) and the MON alias.
- [Cron Every Sunday — 0 0 * * 0](https://devbento.dev/tools/cron/every-sunday): Sunday is both 0 and 7. Weekend only (0,6) patterns and @weekly.
- [Cron Monthly 1st — 0 0 1 * *](https://devbento.dev/tools/cron/monthly-first-day): First day of month. @monthly, last day workaround, day 31 skipping.

## Examples — Base64 File/Image Converters

- [Image to Base64 Converter](https://devbento.dev/tools/base64/image-to-base64): Convert images (JPG, PNG, SVG, WebP, GIF) to Base64. Data URI and CSS background output.
- [JPG to Base64 Converter](https://devbento.dev/tools/base64/jpg-to-base64): Encode JPEG images to Base64 strings. EXIF handling, MIME type details.
- [PNG to Base64 Converter](https://devbento.dev/tools/base64/png-to-base64): Encode PNG images to Base64. Transparency preserved, size optimization tips.
- [SVG to Base64 Converter](https://devbento.dev/tools/base64/svg-to-base64): Encode SVG to Base64 data URIs. URL encoded vs Base64 comparison.
- [WebP to Base64 Converter](https://devbento.dev/tools/base64/webp-to-base64): Encode WebP images to Base64. Smaller than JPEG/PNG for most images.
- [GIF to Base64 Converter](https://devbento.dev/tools/base64/gif-to-base64): Encode GIF images and animations to Base64. Animation preserved.
- [PDF to Base64 Converter](https://devbento.dev/tools/base64/pdf-to-base64): Encode PDF files to Base64 for APIs, databases, and email attachments.
- [File to Base64 Converter](https://devbento.dev/tools/base64/file-to-base64): Encode any file to Base64. MIME detection, size overhead explained.
- [Base64 to Image Decoder](https://devbento.dev/tools/base64/base64-to-image): Decode Base64 strings to viewable, downloadable images. Automatic format detection.
- [Base64 to PDF Decoder](https://devbento.dev/tools/base64/base64-to-pdf): Decode Base64 strings to downloadable PDF files.
- [Base64 to File Decoder](https://devbento.dev/tools/base64/base64-to-file): Decode Base64 to any file type. Magic byte detection for format identification.
- [Audio to Base64 Converter](https://devbento.dev/tools/base64/audio-to-base64): Encode MP3, WAV, OGG, FLAC to Base64 for HTML audio embedding.
- [CSS Background Image Base64](https://devbento.dev/tools/base64/css-background-image): Generate CSS background-image with Base64 data URIs. Performance guidelines.
- [Data URI Generator](https://devbento.dev/tools/base64/data-uri-generator): Create data: URLs from any file. RFC 2397 syntax, CSP considerations.

## Cheat Sheets & Reference Guides

- [Cron Cheat Sheet](https://devbento.dev/tools/cron/cheat-sheet): Every cron expression you'll actually use. Syntax breakdown, field ranges, special characters, aliases, common gotchas.
- [Regex Cheat Sheet](https://devbento.dev/tools/regex/cheat-sheet): Interactive regex quick reference. Metacharacters, quantifiers, anchors, groups, lookaheads, flags, and common patterns.
- [Which HTTP Status Code Should I Use?](https://devbento.dev/tools/http-status-codes/which-code): Decision guide for choosing the right HTTP status code. REST CRUD patterns, redirect rules, error codes.

## Examples — Color Converter

- [HEX to RGB Converter](https://devbento.dev/tools/color/convert/hex-to-rgb): Convert HEX color codes like #3b82f6 to RGB values. Hex shorthand, alpha channels, CSS usage.
- [RGB to HSL Converter](https://devbento.dev/tools/color/convert/rgb-to-hsl): Convert RGB color values to HSL. Color models for CSS, design systems, and programmatic manipulation.
- [Tailwind CSS Color to HEX](https://devbento.dev/tools/color/lookup/tailwind-colors): Look up Tailwind CSS color names and get their HEX values. Quick reference for the Tailwind palette.

## Examples — Code Formatter

- [Format SQL Query Online](https://devbento.dev/tools/code/format/sql-query): Format messy SQL queries with proper keyword alignment. SELECT, JOIN, subqueries, CTEs.
- [Minify CSS Online](https://devbento.dev/tools/code/format/minify-css): Minify CSS by removing whitespace and comments. Size reduction for production.
- [Beautify HTML Online](https://devbento.dev/tools/code/format/beautify-html): Format and indent messy HTML markup. Fix indentation and align attributes.

## Examples — Diff Checker

- [Compare Two Texts Online](https://devbento.dev/tools/diff/compare/text): Side-by-side diff with character-level highlighting. Diff algorithms and unified format.
- [Compare JSON Objects](https://devbento.dev/tools/diff/compare/json): Diff two JSON documents. Find added, removed, and changed keys.

## Examples — Data Converter

- [JSON to YAML Converter](https://devbento.dev/tools/data/convert/json-to-yaml): Convert JSON to YAML. Handles nested objects, arrays, and data types.
- [CSV to JSON Converter](https://devbento.dev/tools/data/convert/csv-to-json): Convert CSV to JSON array of objects. First row becomes keys.
- [YAML to JSON Converter](https://devbento.dev/tools/data/convert/yaml-to-json): Convert YAML config files to JSON. Resolves anchors, validates syntax.
- [ENV to JSON Converter](https://devbento.dev/tools/data-converter/convert/env-to-json): Convert .env files to JSON format instantly. Handles comments, quotes, multi-line values, and auto-types booleans and numbers.
- [Convert JSON to XML Online](https://devbento.dev/tools/data-converter/json-to-xml): Convert JSON data to XML format instantly in your browser. Free, no server upload required.
- [Convert JSON to CSV Online](https://devbento.dev/tools/data-converter/json-to-csv): Convert JSON arrays and objects to CSV format instantly in your browser. Free, no server upload.
- [Convert HTML to JSON Online](https://devbento.dev/tools/data-converter/html-to-json): Extract structured data from HTML tables and lists into JSON. Free browser-based converter.
- [Convert Markdown to JSON Online](https://devbento.dev/tools/data-converter/markdown-to-json): Convert Markdown tables and lists to structured JSON data. Free, runs in your browser.

## Examples — Regex Patterns

- [Email Regex Pattern](https://devbento.dev/tools/regex/test/email-validation): Regex for email validation. RFC 5322 compliance, common pitfalls.
- [URL Regex Pattern](https://devbento.dev/tools/regex/test/url-validation): Regex to match HTTP/HTTPS URLs with query strings, fragments, and ports.
- [IP Address Regex](https://devbento.dev/tools/regex/test/ip-address): Regex for IPv4 addresses. CIDR notation and private range detection.

## Examples — Other Tools

- [Format a JSON API Response](https://devbento.dev/tools/json/format/api-response): Format a sample REST API response. Indent conventions and jq usage.
- [Validate JSON Syntax](https://devbento.dev/tools/json/validate/syntax): Catch trailing commas, single quotes, unquoted keys, and missing brackets.
- [Minify JSON Online](https://devbento.dev/tools/json/minify/compact): Remove whitespace from JSON to reduce file size for API payloads and config files.
- [Decode a JWT Token](https://devbento.dev/tools/jwt/decode/sample-token): Decode a sample JWT. Three part structure, standard claims, security gotchas.
- [Decode Expired JWT Token](https://devbento.dev/tools/jwt/decode/expired-token): Inspect an expired JWT. Check exp claim and troubleshoot authentication issues.
- [URL Encode Query Params](https://devbento.dev/tools/url/encode/query-params): Encode spaces, ampersands, and Unicode. encodeURIComponent vs encodeURI.
- [URL Decode Online](https://devbento.dev/tools/url/decode/percent-encoding): Decode percent-encoded URLs. Converts %20 to spaces, %2F to slashes, decodes UTF-8.
- [SHA-256 Hash of Hello, World!](https://devbento.dev/tools/hash/sha256/hello-world): Verify the SHA-256 hash dffd6021... Covers avalanche effect and password hashing.
- [MD5 Hash Generator](https://devbento.dev/tools/hash/md5/checksum): Generate MD5 hashes. Why MD5 is broken for security but acceptable for checksums.
- [The Y2K38 Problem](https://devbento.dev/tools/timestamp/y2k38-problem): Timestamp 2147483647 overflows on Jan 19, 2038. 32 bit risks and 64 bit fix.
- [Unix Epoch — Timestamp 0](https://devbento.dev/tools/timestamp/unix-epoch): January 1, 1970. Why this date, negative timestamps, seconds vs milliseconds.
- [UUID v4 vs v7](https://devbento.dev/tools/uuid/v4-vs-v7): Random vs time ordered UUIDs. B tree performance, ULID comparison.
- [Count Tokens in a ChatGPT Prompt](https://devbento.dev/tools/tokens/count/sample-prompt): Token count and cost for a sample prompt. BPE tokenization explained.
- [System Prompt Token Counter](https://devbento.dev/tools/tokens/count/system-prompt): Count tokens in LLM system prompts. Context window budget guidelines.
- [Strong Password Generator](https://devbento.dev/tools/password/generate/strong-password): Generate secure passwords. Entropy calculation and NIST guidelines.
- [Generate QR Code from URL](https://devbento.dev/tools/qr/generate/from-url): Create QR codes from URLs. Error correction levels and print size guidelines.
- [Markdown Table Generator](https://devbento.dev/tools/markdown/preview/tables): Create Markdown tables with column alignment. GFM syntax and limitations.

## Examples — Passport Photo

- [US Passport Photo (2x2 in)](https://devbento.dev/tools/passport-photo/us): Create a 2x2 inch US passport photo. 600x600px, white background, DS-160 compliant.
- [UK Passport Photo (35x45mm)](https://devbento.dev/tools/passport-photo/uk): Create a 35x45mm UK passport photo. Light grey background, HMPO compliant.
- [EU Passport Photo (35x45mm)](https://devbento.dev/tools/passport-photo/eu): Create a 35x45mm EU/Schengen biometric passport photo.
- [Canada Passport Photo (50x70mm)](https://devbento.dev/tools/passport-photo/canada): Create a 50x70mm Canadian passport photo. IRCC compliant.
- [India Passport Photo (2x2 in)](https://devbento.dev/tools/passport-photo/india): Create a 2x2 inch Indian passport photo. MEA/Passport Seva compliant.

## Examples — Background Remover

- [Remove Background from Photo](https://devbento.dev/tools/bg/remove-background-from-photo): AI-powered background removal. How the neural network works, best photo types.
- [Remove White Background](https://devbento.dev/tools/bg/remove-white-background): Remove white backgrounds without losing white elements in the subject.
- [Make Background Transparent](https://devbento.dev/tools/bg/transparent-background): Create transparent PNGs with alpha channels. Format support explained.
- [Remove Background Save as PNG](https://devbento.dev/tools/bg/remove-background-png): Background removal with PNG output. File size, resolution, and quality guide.
- [Product Photo Background Remover](https://devbento.dev/tools/bg/product-photo-background): Clean product photos for Amazon, eBay, Etsy. Platform requirements.

## Examples — Mermaid Diagrams

- [Mermaid Flowchart Online](https://devbento.dev/tools/mermaid/flowchart): Build flowcharts with Mermaid syntax. Nodes, edges, shapes, subgraphs, and direction control.
- [Mermaid Sequence Diagram Generator](https://devbento.dev/tools/mermaid/sequence-diagram): Create sequence diagrams with participants, messages, activation bars, loops, and alt blocks.
- [Mermaid ER Diagram Maker](https://devbento.dev/tools/mermaid/er-diagram): Create entity relationship diagrams with entities, attributes, types, and cardinality notation.
- [Mermaid Gantt Chart Online](https://devbento.dev/tools/mermaid/gantt-chart): Create Gantt charts with tasks, durations, dependencies, milestones, and sections.
- [Mermaid Class Diagram Online](https://devbento.dev/tools/mermaid/class-diagram): Create UML class diagrams with classes, interfaces, inheritance, composition, and visibility modifiers.

## Examples — Random String Generator

- [Generate OpenAI API Key: Create Test Keys with Correct Format](https://devbento.dev/tools/random-string-generator/generate-openai-api-key): Generate an OpenAI-format API key with sk- prefix, correct length, and alphanumeric charset. Create test keys for development without touching your real quota.
- [Generate UUID-like Hex IDs for Database Records](https://devbento.dev/tools/random-string-generator/generate-hex-uuid-ids): Create hex strings in UUID format (8-4-4-4-12) for database primary keys, event IDs, and distributed system identifiers. 128 bits of randomness per ID.
- [Generate Bulk Session Tokens for Development](https://devbento.dev/tools/random-string-generator/generate-bulk-session-tokens): Generate multiple cryptographically secure session tokens at once using base64url charset. Perfect for seeding test databases, populating dev environments, or load testing.
- [Generate Readable Coupon Codes for Promotions](https://devbento.dev/tools/random-string-generator/generate-readable-coupon-codes): Create human-friendly coupon codes using uppercase letters and numbers with grouping. Excludes ambiguous characters for easy manual entry over phone or chat.

## Examples — Wcag Contrast

- [Dark Mode Color Contrast Accessibility Checker](https://devbento.dev/tools/wcag-contrast/dark-mode-accessibility): Check if your dark mode colors meet WCAG AA contrast requirements. Test foreground and background pairs for readability in dark themes.
- [Placeholder Text Contrast Ratio WCAG Checker](https://devbento.dev/tools/wcag-contrast/placeholder-text-ratio): Check if your input placeholder text meets WCAG contrast requirements. Placeholder text is a common accessibility failure point.
- [Button Color Contrast Accessibility WCAG Checker](https://devbento.dev/tools/wcag-contrast/button-accessibility): Check if your button colors meet WCAG contrast requirements. Test CTA button foreground and background pairs for accessibility.

## Examples — Password Strength Analyzer

- [Analyzing a Weak Password](https://devbento.dev/tools/password-strength-analyzer/weak-password): See how zxcvbn detects common password patterns and estimates crack times for weak passwords
- [Analyzing a Strong Password](https://devbento.dev/tools/password-strength-analyzer/strong-password): See how a high-entropy passphrase scores against dictionary attacks and brute force estimation

## Examples — Css Units Converter

- [Px to Rem Converter](https://devbento.dev/tools/css-units-converter/px-to-rem): Convert pixels to rem units instantly. Free online CSS px to rem converter with base font size adjustment.
- [Rem to Px Converter](https://devbento.dev/tools/css-units-converter/rem-to-px): Convert rem to pixels instantly. Free online CSS rem to px converter with base font size adjustment.

## Examples — Lorem Ipsum Generator

- [Lorem Ipsum HTML for Web Prototypes](https://devbento.dev/tools/lorem-ipsum-generator/html-for-web-prototypes): Generate Lorem Ipsum placeholder text wrapped in HTML tags with headings, tables, and code blocks for web design prototypes.
- [Multilingual Lorem Ipsum Placeholder Text](https://devbento.dev/tools/lorem-ipsum-generator/multilingual-placeholder-text): Generate Lorem Ipsum placeholder text in 20 languages including Arabic RTL, Chinese, Japanese, and Korean for internationalized web designs.
- [Placeholder Text Generator](https://devbento.dev/tools/lorem-ipsum-generator/placeholder-text): Generate placeholder text for your designs. Lorem ipsum in 20 languages with customizable length and formatting.

## Examples — Svg Toolkit

- [SVG Optimizer: Reduce SVG File Size Online](https://devbento.dev/tools/svg-toolkit/svg-optimizer): Optimize SVG files online with SVGO. Remove metadata, comments, and redundant data. Reduce SVG size by 30-70% without quality loss.
- [SVG Prettifier: Format SVG Code Online](https://devbento.dev/tools/svg-toolkit/svg-prettifier): Format and prettify SVG code with proper indentation. Make SVG files readable with one click. Client-side, no upload needed.
- [SVG Minifier: Minify SVG Files Online](https://devbento.dev/tools/svg-toolkit/svg-minifier): Minify SVG files by removing whitespace and shortening attributes. Get the smallest possible SVG output. Client-side processing.

## Examples — Color Palette

- [Extract Sunset Color Palette from a Photo](https://devbento.dev/tools/color-palette/sunset-palette): Extract warm sunset colors from a photo. See how the tool identifies dominant oranges, pinks, and purples using median cut quantization.
- [Extract Brand Colors from a Logo Image](https://devbento.dev/tools/color-palette/brand-colors): Upload a logo and extract its brand color palette. Identify primary and secondary brand colors for your design system.

## Examples — JWT Generator

- [Generate an HS256 JWT for API Auth Testing](https://devbento.dev/tools/jwt/generate/api-test-token): Generate a signed HS256 JWT with standard claims (sub, name, email, exp) to test API authentication middleware without a real auth server.
- [Generate an RS256 JWT for OAuth2 / OIDC Testing](https://devbento.dev/tools/jwt/generate/rs256-oauth-token): Generate a signed RS256 JWT with RSA key pair for testing OAuth2 and OIDC flows, including iss, aud, sub claims and 24h expiry.

## Examples — Json To Typescript

- [Convert REST API Response to TypeScript](https://devbento.dev/tools/json-to-typescript/json-to-typescript/api-response): Generate TypeScript types from a typical REST API JSON response
- [Convert JSON Config to TypeScript](https://devbento.dev/tools/json-to-typescript/json-to-typescript/config): Generate TypeScript types from a nested configuration object
- [Generate Go Structs from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/go-api-response): Generate Go structs with JSON tags from a typical REST API JSON response
- [Generate Go Structs from JSON Config](https://devbento.dev/tools/json-to-typescript/json-to-typescript/go-config): Generate Go structs with JSON tags from a nested application config object
- [Generate JSON Schema from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/schema-api-response): Generate a JSON Schema from a typical REST API JSON response
- [Generate JSON Schema from JSON Config](https://devbento.dev/tools/json-to-typescript/json-to-typescript/schema-config): Generate a JSON Schema from a nested configuration object
- [Generate Python Dataclasses from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/python-api-response): Generate Python dataclasses with type annotations from a typical REST API JSON response
- [Generate Zod Schemas from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/zod-api-response): Generate Zod schemas with TypeScript type inference from a typical REST API JSON response
- [Generate Rust Structs from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/rust-api-response): Generate Rust structs with serde derives from a typical REST API JSON response
- [Generate Rust Structs from Config Object](https://devbento.dev/tools/json-to-typescript/json-to-typescript/rust-config): Generate Rust structs with serde derives from a nested application configuration
- [Generate C# Classes from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/csharp-api-response): Generate C# classes with JsonPropertyName attributes from a typical REST API JSON response
- [Generate C# Classes from Config Object](https://devbento.dev/tools/json-to-typescript/json-to-typescript/csharp-config): Generate C# classes with JsonPropertyName attributes from a nested application configuration
- [Generate Swift Structs from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/swift-api-response): Generate Swift Codable structs from a typical REST API JSON response
- [Generate Swift Structs from Config Object](https://devbento.dev/tools/json-to-typescript/json-to-typescript/swift-config): Generate Swift Codable structs from a nested application configuration
- [Generate Kotlin Data Classes from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/kotlin-api-response): Generate Kotlin data classes with kotlinx.serialization from a typical REST API JSON response
- [Generate Kotlin Data Classes from Config Object](https://devbento.dev/tools/json-to-typescript/json-to-typescript/kotlin-config): Generate Kotlin data classes with kotlinx.serialization from a nested application configuration
- [Generate Java Classes from API Response](https://devbento.dev/tools/json-to-typescript/json-to-typescript/java-api-response): Generate Java classes with Jackson annotations from a typical REST API JSON response
- [Generate Java Classes from Config Object](https://devbento.dev/tools/json-to-typescript/json-to-typescript/java-config): Generate Java classes with Jackson annotations from a nested application configuration

## Examples — HTTP Status Codes

- [HTTP Status Code Generator](https://devbento.dev/tools/http-status-codes/code-generator): Generate HTTP status codes for your API responses. Quick reference with copy-to-clipboard for 200, 201, 301, 400, 401, 403, 404, 500, 502, and more.

## Examples — Gitignore Generator

- [Gitignore for macOS](https://devbento.dev/tools/gitignore-generator/macos): Generate a .gitignore file for macOS projects. Includes .DS_Store, Thumbs.db, and other OS-specific files.

## Examples — String Tools

- [Slugify String Online](https://devbento.dev/tools/string-tools/string-tools/slugify-string): Convert any text to a URL-safe slug instantly. Remove spaces, special characters, and diacritics to create clean, SEO-friendly slugs.
- [Find and Replace Online](https://devbento.dev/tools/string-tools/string-tools/find-replace-regex): Find and replace text with regex support. Replace literal strings or use regex patterns with configurable flags.
- [Sort Lines Online](https://devbento.dev/tools/string-tools/string-tools/sort-lines): Sort lines of text alphabetically in ascending or descending order. Remove duplicates and empty lines.
- [Reverse String Online](https://devbento.dev/tools/string-tools/string-tools/reverse-string): Reverse any string instantly. Works with ASCII, Unicode, and emoji characters.
- [Case Converter — camelCase, snake_case, kebab-case](https://devbento.dev/tools/string-tools/string-tools/case-converter): Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case, and more.
- [Remove Duplicate Lines Online](https://devbento.dev/tools/string-tools/string-tools/remove-duplicates): Remove duplicate lines from text. Keep first occurrence and remove all subsequent duplicates.
- [Word Frequency Counter Online](https://devbento.dev/tools/string-tools/string-tools/word-frequency): Count word frequency in any text. See which words appear most often, sorted by count.
- [Levenshtein Distance Calculator](https://devbento.dev/tools/string-tools/string-tools/levenshtein-distance): Calculate the edit distance between two strings. See how many single-character edits are needed.
- [ROT13 Decoder Online](https://devbento.dev/tools/string-tools/string-tools/rot13-decoder): Encode or decode ROT13 text. ROT13 is a simple substitution cipher that shifts each letter by 13 positions.
- [Zalgo Text Generator](https://devbento.dev/tools/string-tools/string-tools/zalgo-text): Generate zalgo/glitch text by adding random combining characters to each letter.
- [Truncate Text Online](https://devbento.dev/tools/string-tools/string-tools/truncate-text): Truncate text to a maximum length with ellipsis. Preview truncation before applying.
- [Remove Whitespace Online](https://devbento.dev/tools/string-tools/string-tools/remove-whitespace): Trim whitespace from each line, remove extra spaces, and clean up text formatting.

## About

- All tools run 100% in the browser
- No data collection, no server processing
- https://devbento.dev