Developer Tools That Run in Your Browser
Encoders, hashes, key generators, JSON, JWT, diff, cron and more, running entirely in your browser. No server-side processing, no third-party requests, no tracking.
Data
JSON Format, minify, sort, repair and query JSON with JSONPath, without rounding a big number or dropping a duplicate key. The document stays in the browser. CSV Paste or drop a CSV, TSV or any delimited file and read it as a sortable table beside its own text, with the delimiter worked out for you. Nothing is uploaded. Config Convert a configuration between YAML, JSON, TOML, .env and Java properties, keeping every value's type across the flat formats that have none. Schema Check a JSON payload against a JSON Schema, Zod or Pydantic model with every error marked in place, and convert a schema between all three. Mock Data Generate seeded rows of sample data from a JSON Schema, Zod or Pydantic model — names, emails, addresses, Luhn-valid cards, IBANs, ISBNs — as JSON, CSV or SQL. Unique ID Generate UUIDs v1 through v8 and NanoID, CUID2, ULID, KSUID, XID, TypeID, MongoDB ObjectId, Firebase PushID, Snowflake and Sonyflake IDs, singly or by the batch. Diff Compare two texts side by side, with the changed words marked rather than the whole line and syntax highlighting for sixteen languages. Nothing is uploaded. Markdown Write Markdown with a formatting bar and read it back rendered as you type, side by side or one at a time, in GitHub, CommonMark or original flavour.
Text and encoding
Codec Encode and decode Base64, Base32, hex, decimal, binary, NATO, Morse and gzip, or run text through ROT13, Caesar, Vigenère and XOR. Nothing leaves the browser. String Convert camel, snake, kebab, Pascal, title and sentence case, sort, dedupe, wrap and shuffle lines, slugify, count words, and escape for HTML, JS, C, shell and SQL. Unicode Names, categories, scripts, UTF-8, UTF-16 and UTF-32 bytes, every escape form, NFC/NFD/NFKC/NFKD, and the invisible, bidi and lookalike characters hiding in a text. Regex Write a regular expression, watch every match and capture group light up in your own text, and read a line-by-line breakdown of what the pattern does. URL Take a URL apart into scheme, host, port, path, query and fragment, and edit its query parameters unescaped in a builder that stays in step with the address. Hex Open any file and read every byte of it, in hex and as text, patch the bytes in place, search for a signature, then save the file back out. Nothing is uploaded.
Security
Hasher Hash text or a file with MD5, SHA-1, SHA-2, SHA-3, BLAKE2, BLAKE3, CRC32, xxHash or MurmurHash, or derive a key with Argon2, bcrypt, scrypt or PBKDF2, in the tab. Cryptography Encrypt and decrypt text or a file with AES-GCM, AES-CBC, AES-CTR, ChaCha20-Poly1305, NaCl secretbox and box, OpenPGP, or age with post-quantum keys. Keygen Generate SSH, PGP, WireGuard and age keys — post-quantum ML-KEM included — plus JSON Web Keys and random secrets. The private half never leaves your browser. JWT Read a JSON Web Token's header and claims, check its signature or decrypt a JWE, and build, sign or encrypt a new one. Every key is made and used in the tab. Certificate Decode a certificate, a signing request or an SSH key — names, expiry, fingerprints, chain order — or generate a self-signed one, a root CA, or one signed by it. OTP Work out a TOTP, HOTP or OCRA one-time password from a shared secret, with the algorithm, digits, counter and challenge the token uses. The secret never leaves the tab. Password Generate a strong random password at the length and mix of lowercase, uppercase, digits and symbols you want, or a memorable passphrase made of real English words.
Time and place
Time Convert a Unix timestamp across time zones and read it as ISO 8601 or RFC 2822, parse a duration like 1h 30m or PT1H30M, and count the days between two dates. Cron Write or read a cron expression field by field, in Unix or Quartz flavour, and see the next runs in your own time zone or UTC before you schedule it. Countries Pick any of 250 countries and read back its ISO 3166 codes, calling code, capital, currencies, languages, land borders, area and name in two dozen languages. Phone Number Parse a phone number against any of 245 dialling regions, see whether it is valid, where its range was issued, who carries it and what time it is there.
Everyday
Calculator Add, shift, rotate and mask 8- to 64-bit words in hex, octal or decimal, with every bit on screen and read as an IEEE 754 float — or switch to trigonometry. Converter Convert distance, area, volume, mass, temperature, speed, data, energy, power and pressure between metric, imperial and SI units, to twelve digits. Colour Convert between hex, RGB, HSL, CMYK, LAB and OKLCH, check WCAG contrast, build a palette in OKLCH, and see any of it through colour blindness. Image Open a picture, read and edit its EXIF and metadata, crop, resize, turn and colour it, then save it as PNG, JPEG, WebP or AVIF, or as a data URI. Nothing is uploaded. DOCX Open a Word document and read it as the pages it prints on, or edit its text, tables and styles and save it back as .docx. Nothing is uploaded. PDF Open a PDF to read it, or highlight, draw, add text, pictures and a signature, and save the marks into the file. Nothing is uploaded. QR Code Make a QR code for a link, a WiFi network, a contact card, an email, a phone number or an SMS, drawn as you type and saved as an SVG or a PNG. Nothing is fetched.