Developer tools
Format JSON, decode a token, hash a string, generate UUIDs, test a regular expression — the small jobs that interrupt a working day. Every one of them runs in this tab: nothing you paste is uploaded, which matters when the thing you are pasting is a token, a hash input or a password. There is no engine to download and no wait; the page is ready when it loads. Working with prose rather than code? The text tools are next door.
JSON & structured data
- JSON formatter and validator — pretty-print, minify, find errorsFormat, minify and validate JSON with the exact line and column of any error. Also reports duplicate keys and numbers that lose precision. In your browser.
- JSON to YAML to CSV converter — all directions, free onlineConvert between JSON, YAML and CSV in any direction. Nesting flattened into dotted columns for CSV, never discarded. Runs in your browser.
- JSON to TypeScript — generate interfaces from a JSON sampleGenerate TypeScript interfaces from a JSON sample. Nested objects become named interfaces; optionality is inferred and the rules are stated. In your browser.
- HTML, CSS and JavaScript beautifier and minifier — free onlineBeautify or minify HTML, CSS and JavaScript in your browser. Comments and whitespace only — nothing is renamed and nothing can break.
Encoding & hashing
- Base64 encoder and decoder — text and files, in your browserEncode text or any file to base64, and decode base64 back to text or a downloadable file. Strict decoding that reports bad input. Nothing uploaded.
- URL encoder and decoder — percent-encoding, both modesPercent-encode and decode URLs. Choose whether you are encoding a value inside a URL or a whole address — the two give different results. In your browser.
- Hex to text and text to hex converter — free onlineConvert text to hexadecimal and back, with your choice of separator. Strict decoding that says exactly what is wrong. Runs in your browser.
- Hash generator — MD5, SHA-1 and SHA-256 of any textGenerate MD5, SHA-1 and SHA-256 hashes of text in your browser. Nothing is uploaded, which matters when the input is a secret.
Identifiers & time
- UUID generator — version 4 UUIDs, single or in bulkGenerate version 4 UUIDs in your browser, one at a time or a hundred at once. Uses the cryptographic random number generator. Copy individually or all at once.
- Unix timestamp converter — epoch time to date and backConvert Unix timestamps to human dates and back, in any timezone. Handles milliseconds, pre-epoch dates and daylight-saving edge cases. In your browser.
Compare & test
- Find invisible characters in text — zero-width spaces, BOM, non-breaking spacesLocate and strip zero-width spaces, byte-order marks and control characters that break identifiers, CSV imports and JSON parsing. Client-side, nothing uploaded.
- Slugify text — URL-safe identifiers from any stringGenerate URL-safe slugs for routes, filenames and CMS keys. Handles Cyrillic, accents, emoji and punctuation. Client-side, nothing uploaded.
- Text diff — compare two texts and see what changedCompare two blocks of text by line, word or character. Additions and removals are marked, not just coloured. Runs in your browser, nothing uploaded.
- Regex tester — test a regular expression against sample textTest a regular expression, see every match with its position and capture groups, and get told when a pattern is too slow instead of freezing the page.
Security
- Password generator — strong random passwords, generated in your browserGenerate strong random passwords with the length and character types you choose. Uses your browser's cryptographic random generator. Nothing is sent anywhere or stored.
- JWT decoder — read the header and payload of a tokenDecode a JSON Web Token to see its header, payload and claim dates. Decoding only — the signature is never verified. Nothing is uploaded.