82 tools · Developer Utilities
Developer Utilities tools
Formatters, generators, and regex tools for daily dev work.
Popular in developer utilities
Developer Utilities
JSON Formatter
Paste JSON to format, validate, and minify. Clear error messages with line numbers. Free and runs in your browser.
Developer Utilities
JSON to CSV Converter
Convert JSON arrays to CSV instantly. Auto-detects headers, handles nested fields, exports to file.
Developer Utilities
Base64 Encoder & Decoder
Encode text to base64 or decode base64 back to text. UTF-8 safe. Runs entirely in your browser.
Developer Utilities
URL Encoder & Decoder
Encode URLs for safe use in links and query strings, or decode encoded URLs back to readable text.
Developer Utilities
Regex Tester
Test regular expressions against sample text with live match highlighting. Supports common flags and groups.
Developer Utilities
UUID Generator
Generate one or many UUIDs (v4 random or v1 timestamp). Copy single or bulk, free and runs locally.
More developer utilities tools
- Markdown to HTML ConverterPaste Markdown, get clean HTML. Supports tables, code blocks, and task lists. Runs in your browser.
- Password GeneratorGenerate strong random passwords. Choose length, symbols, numbers, and avoid lookalikes. Runs locally.
- Password Breach CheckerCheck if a password has appeared in a known data breach. Uses HaveIBeenPwned k-anonymity — your password never leaves the browser.
- What Is My IPSee your public IP, approximate city, ISP, and time zone. Live, in your browser — we never see the request.
- QR Code GeneratorGenerate QR codes for URLs, text, wifi, or email. Customize size and error level. Download PNG or SVG — free and offline.
- Hash GeneratorGenerate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text or file. Client-side — your input never leaves the browser.
- CSS MinifierPaste CSS, strip comments and whitespace, and get a smaller minified version. Offline, safe, no ads or sign-ups.
- JavaScript MinifierPaste JavaScript and shrink it by stripping comments and whitespace. A fast, safe in-browser minifier — no accounts.
- XML FormatterPaste XML — get a clean, indented version plus a syntax check. Runs entirely in your browser, no uploads.
- Diff CheckerPaste two blocks of text and see what changed line-by-line. Great for contracts, code, and writing revisions.
- JWT DecoderPaste a JWT — see header, payload, and signature decoded. Client-side only, your token never leaves the browser.
- HTML FormatterPaste HTML — get a cleanly indented version or a minified one. In-browser, safe, no ads.
- SQL FormatterClean up a messy SQL query with proper indentation and line breaks for SELECT, JOIN, WHERE, GROUP BY. Free.
- Password Strength CheckerCheck how strong a password is — entropy bits, estimated time to crack, and what to improve. Private, offline.
- URL CleanerPaste a URL with tracking — utm_*, fbclid, gclid, ref, etc. — and get a clean version. Privacy-friendly and free.
- Color PickerInteractive color picker with HEX, RGB, HSL, and alpha. Paste a color to convert, or pick from a gradient.
- CSS Gradient GeneratorBuild linear and radial CSS gradients with multiple color stops and angles. Copy the CSS snippet instantly.
- Barcode GeneratorGenerate Code 128 or EAN-13 barcodes from any text or number. Download as PNG or SVG — free, no sign-up.
- Favicon GeneratorUpload an image and get favicons in every size a modern site needs — 16, 32, 48, 180, 192, 512 PNGs + ICO.
- Meta Tag GeneratorBuild SEO-ready meta tags — title, description, Open Graph, Twitter Card — and copy the HTML block instantly.
- Robots.txt GeneratorGenerate a valid robots.txt for your site with disallow rules, allow overrides, and a sitemap link. Free.
- Open Graph GeneratorBuild Open Graph and Twitter Card tags to make your links render beautifully on Facebook, LinkedIn, X, Slack.
- Keyword Density CheckerPaste an article and see the frequency of each word and 2-3 word phrase. Essential for SEO content optimization.
- Schema Markup GeneratorGenerate valid JSON-LD for Article, Product, LocalBusiness, BreadcrumbList, and more. Copy straight into your <head>.
- FAQ Schema GeneratorEnter Q&A pairs and get valid FAQPage JSON-LD — the exact markup Google uses for FAQ rich results in search.
- XML to JSON ConverterConvert XML documents to JSON in your browser. Preserves attributes and nested elements. No upload — runs locally.
- JSON to XML ConverterConvert JSON to well-formed XML with indentation. Control root element name, attribute prefix, and wrapper rules.
- YAML FormatterPaste YAML and get it validated, indented, and pretty-printed. Catch common mistakes like tab characters and bad anchors.
- JSON Diff CheckerCompare two JSON payloads and see added, removed, and changed keys highlighted. Deep-diff works across nested objects.
- HTML Entity Encoder & DecoderEncode or decode HTML entities like &, <, ©. Paste any text and flip between raw and escaped in one click.
- Cron Expression BuilderBuild cron schedules visually — minute, hour, day, month, weekday — and copy the string for crontab or GitHub Actions.
- Cron Expression ExplainerPaste a cron expression and read it in plain English with next 5 run times. Supports standard, Quartz, and Jenkins syntax.
- HTTP Status Code LookupSearch every HTTP status code — 200, 301, 404, 500, and the obscure ones. With RFC references and plain-English meaning.
- MIME Type LookupLook up the correct Content-Type for any file extension and vice versa — images, fonts, video, JSON, and more.
- URL ParserPaste any URL and see its protocol, host, port, path, query string, and fragment broken out — like window.location, live.
- Query String ParserParse any URL's query string into key/value pairs, including repeated keys, arrays, and URL-encoded values.
- Filename CleanerClean filenames by removing illegal characters, trimming length, and collapsing spaces. Safe on Windows, macOS, and Linux.
- Line CounterCount total lines, blank lines, comment lines, and code lines in any paste. Great for LOC estimates and log review.
- Box Shadow GeneratorBuild any CSS box-shadow with a live preview — offset, blur, spread, color, inset. Copy the rule in one click.
- Border Radius GeneratorDesign CSS border-radius with four independent corner controls. Copy the exact rule or the full 8-value shorthand.
- CSS Clamp GeneratorGenerate responsive CSS clamp() values for fluid typography or spacing. Enter min/max screen widths, get the rule.
- Flexbox PlaygroundExperiment with justify-content, align-items, direction, and wrap. See the CSS update live as you drag controls.
- Grid Layout GeneratorBuild a CSS grid visually — columns, rows, gap, named areas — and copy the exact grid-template-areas rule.
- Aspect Ratio CalculatorKeep images and video in proportion — enter width or height, get the matching dimension for any aspect ratio.
- Image Dimensions CheckerDrop any image to see its exact pixel width, height, aspect ratio, and file size. Everything stays in your browser.
- Contrast CheckerCheck color contrast against WCAG AA and AAA targets for normal and large text. Live preview and pass/fail badges.
- Social Media Image SizesUp-to-date image size reference for Instagram, X, Facebook, LinkedIn, TikTok, YouTube. Post, cover, story, thumbnail.
- Mock Data GeneratorGenerate realistic fake JSON — users, emails, phones, addresses — for testing, demos, and seeding databases.
- JSON to TypeScript InterfacePaste any JSON and get matching TypeScript interfaces. Handles nested objects, arrays, optional and nullable fields.
- CSS to TailwindPaste a CSS rule and get the equivalent Tailwind utility classes. Great for migrating legacy stylesheets.
- Tailwind to CSSPaste Tailwind class names and get the underlying CSS rules. Useful for emails, PDFs, and non-Tailwind codebases.
- HTML to JSXConvert HTML to valid JSX — class→className, inline styles to objects, self-closing tags, and SVG fixes.
- SQL to JSONPaste SQL INSERT statements and export the rows as JSON. Handles quoted strings, nulls, and numeric types.
- Gitignore GeneratorPick your stack — Node, Python, Go, Rust, Java, Unity, Xcode — and get a ready-to-paste .gitignore file.
- README GeneratorAnswer a few questions — name, description, install, usage, license — and get a clean GitHub-ready README.md.
- Regex BuilderBuild regex from checkboxes — digits, letters, anchors, groups — with a live preview against your test text.
- Discord Timestamp GeneratorPick a date and time, get all Discord timestamp formats (short date, long date, relative). Copy-paste ready.
- Sitemap URL GeneratorPaste a list of URLs and get a valid sitemap.xml with changefreq, priority, and lastmod. Ready for Google Search Console.
- JSON Schema GeneratorPaste a JSON sample and get a draft-07 JSON Schema with inferred types, required fields, and nested structure.
- JWT GeneratorCreate HS256/HS384/HS512-signed JWT tokens from a header, payload, and secret. Runs entirely in your browser.
- Env File ParserPaste a .env file and get a validated list of keys, values, and parse errors. Detects duplicates and bad quoting.
- User Agent ParserPaste a User-Agent string and get the browser, OS, device, and engine parsed out. Useful for log analysis.
- cURL Command BuilderFill in URL, method, headers, and body to get a copy-pasteable curl command. Supports auth, query params, JSON bodies.
- Regex to EnglishPaste a regular expression and get a plain-English walkthrough of what it matches, group by group.
- TOML to JSONPaste TOML (like a Cargo.toml or pyproject.toml) and get equivalent JSON. Runs in your browser — no upload.
- Dockerfile Lint HelperScan a Dockerfile for common smells — latest tag, no USER, ADD for URLs, secrets in RUN, missing HEALTHCHECK, and more.
- Git Commit Message HelperBuild a conventional-commit message from type/scope/subject/body — ready to paste into git commit.
- Semver BumperBump a version across major/minor/patch — see exactly what changes and when to pick each.
- Bash Command ExplainerPaste any bash pipeline — get a plain-English explanation of each command and its flags.
- API Rate Limit CalculatorGiven req/sec limit, concurrency, and latency — compute effective throughput and when you'll saturate.
- JSON Schema to TypeScriptPaste a JSON sample — get a clean TypeScript interface inferred automatically.
- OpenAPI Endpoint CounterPaste an OpenAPI 3 spec — see paths by method, operation IDs, and count endpoints at a glance.
- HTTP Header ExplainerPaste raw headers — get plain-English meanings and security implications for each Cache-Control, CSP, HSTS.
- WebSocket Frame ParserDecode raw WebSocket frame bytes — FIN, opcode, mask, payload length, masking key, and unmasked payload.
- Dotenv GeneratorTurn a VAR=value list into a validated .env file — with auto-generated 32-hex secrets and duplicate detection.
- Tech Repair Worth It CalculatorRepair vs replace decision for phones, laptops, TVs, consoles. 50%/75% value rule applied.