62 tools · no sign-up · no uploads
Fast developer tools that run entirely in your browser
By developers, for developers.
Small, focused utilities for everyday development work — formatting, decoding, hashing, comparing. Every one runs entirely in your browser, so nothing you paste is ever sent to a server.
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Convert
- Docker Run ↔ Compose ConverterConvert a docker run command into a compose service, or a compose service back into a docker run command.
- Base ConverterEncode and decode Base64, Base32 and Base58 in one tool — text or file, with format-specific options for each.
- URL Encoder & DecoderPercent-encode or decode URLs, and break one down into its parts.
- Timestamp ConverterConvert Unix epoch timestamps to dates and back, with a live current time.
- Color ConverterConvert between HEX, RGB, HSL and OKLCH, with WCAG contrast checking.
- Chmod CalculatorConvert Unix file permissions between octal and symbolic notation with a checkbox grid.
- JSON, YAML, CSV & XML ConverterConvert data between JSON, YAML, CSV and XML in either direction.
- JSON & XML to TypesTurn a JSON or XML sample into TypeScript, Go, Java, C#, Kotlin, Swift, Rust or Python types automatically.
Format
- JSON FormatterBeautify, minify, validate and repair broken JSON entirely in your browser.
- HTML / CSS / JS MinifierShrink HTML, CSS or JavaScript by stripping comments and unnecessary whitespace.
- SQL FormatterBeautify a SQL query with consistent indentation and keyword casing.
- XML FormatterPretty-print, minify, validate, or convert XML to JSON — all in the browser.
- Markdown PreviewerLive-preview Markdown as HTML, or convert HTML back into Markdown, right in your browser.
Generate
- QR Code GeneratorTurn text or a URL into a scannable QR code — download as PNG or SVG.
- UUID GeneratorGenerate v4 or time-ordered v7 UUIDs in bulk, and inspect existing ones.
- Lorem Ipsum GeneratorGenerate Lorem Ipsum placeholder text as paragraphs, sentences or words.
- Fake Data GeneratorGenerate realistic fake names, emails, addresses and more as JSON or CSV.
- Barcode GeneratorTurn text or digits into a real, scannable Code 128, Code 39, EAN-13, or UPC-A barcode.
- cURL Command BuilderTurn a method, URL, headers, body and auth into a correctly-escaped curl command.
- Slug GeneratorTurn a title into a clean, URL-friendly slug — separator, casing and length options.
- Meta Tag & Open Graph GeneratorBuild SEO, Open Graph and Twitter Card meta tags for a page, with a live search-result and social-card preview.
- JSON-LD Schema GeneratorBuild Article, Product, FAQ, How-to, Organization or Breadcrumb structured data from a form, ready to paste in.
- Mermaid Diagram GeneratorWrite Mermaid syntax and see the diagram render live — flowcharts, sequence diagrams, ER diagrams and more.
Security
- Password GeneratorCreate strong random passwords with adjustable length and character types.
- Hash GeneratorCompute MD5, SHA-1 and SHA-2 digests, and verify a checksum against them.
- JWT DebuggerDecode, verify and sign JSON Web Tokens without uploading them anywhere.
- Bcrypt GeneratorGenerate a bcrypt hash from a password, or verify a password against one.
- CSP Header Builder & AnalyzerBuild a Content-Security-Policy header directive by directive, or paste one to get it linted and explained.
- security.txt GeneratorBuild a security.txt file per RFC 9116, with validated Contact, Expires and Canonical fields.
- AES Encrypt / DecryptEncrypt and decrypt text or files with AES (GCM, CBC or CTR) using a passphrase or a raw hex key.
- RSA Encrypt / DecryptEncrypt text with an RSA public key and decrypt it with the private key (RSA-OAEP), or generate a new key pair.
Text
- Regex TesterTest regular expressions with live highlighting, groups and replace preview.
- Word CounterCount words and characters, convert text case, and find and replace text — all in your browser.AI
- Diff CheckerCompare two texts or JSON documents and see exactly what changed.
- Case ConverterConvert text between nine common casing styles, plus a smarter AI-assisted Sentence case — all in your browser.AI
- Duplicate Line RemoverFind duplicate lines, sentences, or paragraphs and remove one, some, or all of them — all in your browser.
- Invisible & Homoglyph InspectorDetect hidden zero-width characters, bidi overrides, and spoofing homoglyphs in text, then clean them in your browser.
- ASCII Text Banner GeneratorConvert any text into big block-letter ASCII art — pick the fill character, size and spacing, then copy or download.
AI
Web & Network
- Bundle Size CheckerCheck an npm package's real gzipped size, README and project health, or size a whole package.json at once.
- ASCII, Unicode & Keycode InspectorBrowse the ASCII table, look up any Unicode character's code point and encoding, and see live keydown events.
- Cron Expression ExplainerExplain a cron expression in plain English and see its next run times.
- Cron GeneratorBuild a cron expression with checkboxes and dropdowns instead of writing it by hand.
- CIDR / Subnet CalculatorCalculate network address, broadcast address, host range and mask from a CIDR block.
- User-Agent ParserParse a User-Agent string into browser, OS, rendering engine and device type.
- URL ParserDecompose a URL into its parts and edit its query parameters live.
- Browser Fingerprint InspectorShows what your browser reveals via JavaScript, plus what the server already sees — IP, headers, fonts, and more.
Images
- Image CompressorCompress JPEG, PNG, or WebP images in your browser — batch multiple files, compare before/after, download as a zip.
- Background RemoverCut a photo's background out using an AI model that runs entirely in your browser — no upload required.AI
- Image Format ConverterConvert one or many images between PNG, JPEG, WebP, BMP and ICO — including SVG rasterization — right in your browser.
- Favicon GeneratorGenerate a full favicon package — favicon.ico, PNG sizes, manifest and HTML snippet — from one uploaded image.
- Image CropperCrop an image to a selected area and resize it to exact pixel dimensions, right in your browser.
- Image UpscalerEnlarge a photo 2x-8x with a sharp Lanczos resample — right in your browser, no upload required.
- Image ↔ Base64 ConverterConvert an image to base64 for inlining in CSS/HTML, or decode base64 back into an image.
- SVG OptimizerStrip comments, metadata, and editor cruft from SVG markup — tune precision, compare before/after, download.
- Face & Plate BlurBlur or black out faces, license plates, or anything else sensitive in a photo — right in your browser.AI
- ASCII Art GeneratorConvert an image into ASCII text art — pick the character set, width and contrast, then copy or download it.
CSS
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Why these tools are different
Nothing leaves your browser
Every tool is pure client-side JavaScript. There is no backend and no database, so pasting a JWT, an API response or a config file here does not transmit it anywhere. Open your browser's Network tab and check — you will see no requests.
Fast, because there is nothing to load
Pages are static HTML with one small interactive component. No framework bundle, no tracking scripts, no cookie wall between you and the thing you came to do.
No sign-up, no limits
No account, no rate limit, no "upgrade to process files over 1MB". These are small utilities and they should just work.