38 tools

Developer tools, nothing uploaded.

The small utilities you use daily, without pasting secrets into someone else's server.

File checksumWork out a file's SHA-256 and check a download arrived intact. File to Base64Turn any file into Base64 text or a ready-to-paste data URI. URL encoderPercent-encode text for URLs, or decode it back. HTML entitiesEscape markup characters so they display as text, or decode them back. Hash generatorProduce a SHA hash of any text, using the browser built-in crypto. UUID generatorGenerate version 4 UUIDs from a secure random source. Timestamp converterTurn a Unix timestamp into a readable date, and back again. Base converterConvert a number between binary, octal, decimal and hexadecimal. Color converterConvert a colour between HEX, RGB and HSL, with a preview. Password generatorGenerate strong random passwords in your browser, never over a network. JWT decoderRead the header and payload of a token without sending it anywhere. Regex testerTry a pattern against real text and see every match and capture group. QR code generatorTurn a link or any text into a QR code, generated on your own device. XML formatterIndent XML so it can be read, and find out exactly where it breaks. Base64 decoderTurn Base64 back into the file, image or text it came from. Cron expression explainerPaste a cron line and find out when it actually runs. Text to binaryConvert text to binary, hex, octal or decimal — and back again. SRT to VTT converterConvert between SRT and VTT, and shift every timing at once. HTML to MarkdownTurn markup into clean Markdown you can paste anywhere. Password strength checkerSee how long a password would take to crack — without sending it anywhere. Color contrast checkerCheck whether text will actually be readable, against the accessibility standard. JSON diffCompare two JSON documents by structure, not by text. Encrypt textProtect a message with a passphrase, using real AES-256 that never leaves your device. XML to JSON converterConvert XML to JSON or back, in the page. UTM link builderBuild a tracking link your analytics will group correctly. CSS gradient generatorBuild a gradient visually and copy the CSS. Barcode generatorMake a barcode as a downloadable PNG, in the page. CSS box-shadow generatorDrag the sliders and copy the CSS. SQL formatterIndent a query so it can be read, in your own browser. Code formatterBeautify code so it can be read, or minify it for shipping. YAML formatterPaste YAML. Get it back clean, or get told exactly which line is wrong. Meta tag generatorFill in the fields, copy the tags into your page's head. Border radius generatorSet each corner and copy the CSS. clip-path generatorPick a shape, adjust it, copy the CSS. No image needed. Flexbox generatorSet the properties and read, in plain English, what they actually do. HMAC generatorSign a message with a secret key. Nothing is transmitted. URL parserPaste a URL and see every part of it, with the query parameters decoded. HTTP status codesSearch by number or by name. What each code means and when to use it.

About these tools

Most online developer tools are someone else's server. That is fine for a colour conversion and genuinely reckless for a JWT or an API payload. Everything here runs locally, which is the only sensible arrangement for values that might be credentials.

Guides

FAQ

Developer tools — questions

Are these developer tools free?

Yes — every tool here is free, with no account, no quota and no watermark.

Are my files or text uploaded?

No. Every tool on this page runs inside your own browser. Nothing is transmitted to us or to anyone else.

Do I need to install anything?

No. Everything runs in the page using your browser's own capabilities.