Free Developer Tools: JSON, Base64, Regex and More

ASCII Table The 128 ASCII codes in decimal, hex, octal and binary, each with its character or control code name such as NUL or ESC. Search and filter.

Base32, Base58 and Z85 Encoder Encode text to Base32, Base32hex, Base58, Ascii85 or Z85, or decode it back, with the RFC 4648 test vectors. Runs in your browser; nothing is uploaded.

Base64 Encode and Decode Encode text to Base64 or decode it back, in UTF-8, with the URL-safe alphabet of RFC 4648. It runs in your browser, so nothing you paste is sent anywhere.

Bitwise Calculator Calculate AND, OR, XOR, NAND, NOR, NOT, shifts and rotations of 8 to 64-bit values, with inputs in decimal, hex or binary and a table of every bit.

Border Radius Generator Round each corner of a box with its own horizontal and vertical radius. The shortest border-radius CSS is written for you, with a live preview to copy.

Box Shadow Generator Build a CSS box-shadow with several layers, inset shadows, blur, spread and colour with opacity. See the preview at once and copy the CSS code.

Chmod Calculator Set owner, group and other permissions with check boxes, or type an octal or symbolic mode. Get the chmod command, with setuid, setgid and sticky bits.

Contrast Checker Check the contrast ratio of a text colour and its background. See which WCAG 2.2 levels pass and get the nearest colour that passes AA.

Cron Expression Explainer Explain a cron expression in plain words and see its next run times in your time zone. Lists, ranges, steps, names and macros such as @daily all work.

CSS Clamp Generator Make a fluid CSS clamp() value for font size or spacing from the smallest and largest size and viewport width. The slope and each step are shown.

CSS Clip-Path Generator Build a CSS clip-path with polygon, inset, circle or ellipse. Drag the points of a polygon on the preview, type exact values, and copy the CSS rule.

CSS Gradient Generator Build a linear, radial or conic CSS gradient with two to six colour stops. See it live as you change it, then copy the background declaration.

CSS Grid Generator Build a CSS grid layout: columns and rows with fr, px, auto, minmax() and repeat(), gaps, and named areas painted on the grid. Copy the CSS.

CSS Minifier and Beautifier Minify CSS by removing comments and spaces and shortening colours and zeros, or beautify it to read. See the bytes before and after, and copy the result.

CSS Specificity Calculator Calculate the specificity of a CSS selector as (a, b, c) and see which of two selectors wins. Counts IDs, classes, attributes, pseudo-classes and types.

CSV to JSON Converter Convert CSV into a JSON array of objects. The separator is found on its own, quoted fields and line breaks are read per RFC 4180, and each error gives its line.

CSV to TSV Converter Convert CSV or semicolon text to TSV in your browser, with quoted commas and doubled quotes read by RFC 4180. Cells that TSV cannot hold are reported.

Cubic Bezier Editor Drag the two control points of a cubic-bezier easing curve, try the CSS presets and watch a ball move with the curve. Copy the timing function.

cURL to Python Converter Paste a curl command and get matching Python requests and JavaScript fetch code, with the method, headers, body, Basic auth and query string translated.

EditorConfig Generator Choose indentation, line endings, charset and whitespace rules to get a .editorconfig file with Markdown, YAML and Makefile sections, each line explained.

File Checksum Verifier Compute the MD5, SHA-1, SHA-256, SHA-384, SHA-512 and CRC-32 checksums of your files in the browser, then compare them with the checksum a download page gives.

Flexbox Generator Build a CSS flex container with direction, wrap and alignment, then set grow, shrink and basis for each item. See the preview and copy the CSS.

Gitignore Generator Pick languages, frameworks, editors and systems to merge 51 github/gitignore templates into one .gitignore file, without repeated lines. Copy or download it.

Hash Generator: MD5, SHA-1, SHA-256 Compute the MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of a text, or HMACs when you add a key. It runs in your browser, and the text is never uploaded.

Hex Viewer Open a file or paste text and read it as a hex dump, with offsets and ASCII, search for bytes or text, and inspect the bytes as integers and floats.

HMAC Generator: SHA-1, SHA-256, SHA-512 Compute HMAC-SHA-1, SHA-256, SHA-384 and SHA-512 of a message with a key typed as text, hex or Base64. Hex and Base64 results; computed in your browser.

HTML Entity Encoder and Decoder Encode HTML special characters or accented letters as named or numeric entities, or decode every &name; and &#number; reference. Runs in your browser.

HTML Table Generator Make an accessible HTML table with a caption and header cells that have a scope. Type the cells or paste CSV or TSV, see a preview and copy the markup.

HTML to Markdown Paste HTML and get CommonMark Markdown with headings, emphasis, lists, links, images, code and quotes, and the characters Markdown needs escaped.

HTTP Status Codes Look up an HTTP status code or search its name: meaning, class, the RFC that defines it, cache rules, and a table of all registered codes.

IEEE 754 Converter Convert a decimal number to IEEE 754 half, single or double precision bits, and back. Shows the sign, exponent, fraction, exact stored value and error.

JSON Diff and Patch Compare two JSON documents and list each added, removed and changed value by JSON Pointer path, with an RFC 6902 JSON Patch. Array order can be ignored.

JSON Formatter and Validator Paste JSON to format it with two or four spaces, a tab or no spaces, sort the names A to Z, and see whether it is valid, with the line and column of any error.

JSON to CSV Converter Convert a JSON array of objects to CSV, one column per name, nested objects as columns like address.zip, with RFC 4180 quoting. Made in your browser.

JSON to Go Struct Turn JSON into Go structs with json tags, in your browser. Objects become structs, lists become slices and numbers int64 or float64.

JSON to TOML Converter Convert a JSON object to a TOML 1.0.0 file in your browser. Nested objects become tables, object lists become arrays of tables, integers keep every digit.

JSON to TypeScript Interfaces Paste a JSON sample and get TypeScript interfaces: nested names from the keys, optional fields for missing keys, union types and arrays. Runs in your browser.

JSON to XML Converter Convert JSON to XML with a clear mapping: @ names become attributes, #text becomes element text, arrays become repeated elements. Runs in your browser.

JSON to YAML Converter Convert JSON to YAML 1.2 with two or four spaces of indentation. Names keep their order, whole numbers keep every digit, and the data reads back the same.

JSONPath Tester Run a JSONPath query from RFC 9535 on pasted JSON. See every match with its normalized path, with filters, slices and the functions length and count.

JWT Decoder Decode a JWT to read its header, claims and expiry date in plain language. It only decodes: the signature is not verified, and the token stays in your browser.

JWT Generator and Checker Write a JWT header and payload, set iat, nbf and exp, sign with HS256, HS384 or HS512, and check a pasted token. Signing runs in your browser.

License Generator Fill in the year and holder of an open-source licence such as MIT, Apache-2.0 or GPL-3.0, and compare the terms of ten licences. Copy or download the text.

Markdown Table Generator Turn CSV or TSV into a GitHub Flavored Markdown table with aligned columns and escaped pipes, or read a Markdown table back to CSV. Copy the result.

Markdown to HTML Converter Convert Markdown to HTML with tables, task lists and fenced code. See the rendered preview at once, copy the HTML or download it as a .html file.

MIME Type Finder Find the MIME type of a file extension such as pdf or png, or the extensions of a type such as image/jpeg, from the IANA registry and Apache's list.

Password Breach Checker Check whether a password appears in known data breaches. Your browser hashes it and sends only the first five characters of the hash.

Password Generator Generate random passwords of 4 to 128 characters, or passphrases of random words, with the entropy in bits and a strength label. Nothing is stored.

Password Strength Checker Check how strong a password is: entropy in bits, estimated guesses, time to crack at stated rates and NIST SP 800-63B checks. Nothing is sent.

PIN Generator Generate random numeric PINs of 4 to 12 digits, leaving out runs such as 1234, repeated digits and the most common PINs. Shows the entropy in bits.

Port Number Lookup Look up a port number such as 443 or a service name such as https in the IANA port registry: TCP and UDP entries, the port range and the RFC.

PX to REM and EM Converter Convert px to rem or em with your base font size, see a table of common sizes, and convert every px value in a CSS snippet at once. Runs in your browser.

QR Code Generator Make a QR code for a link, text, Wi-Fi network, contact card, e-mail, phone number or SMS. Choose the size and colours, then download PNG or SVG.

Regex Tester Test a regular expression on your own text. Each match is highlighted, listed with its position and capture groups, and you see the replaced result.

RSA Key Pair Generator Generate an RSA key pair of 2048, 3072 or 4096 bits for OAEP or PSS, in PEM and JWK, in your browser. Keys are never sent anywhere. Not for high-value secrets.

SemVer Calculator Compare semantic versions by SemVer 2.0.0 precedence, bump them, and check whether a version satisfies an npm range such as ^1.3.0 or ~1.2.

SQL Formatter Format SQL with upper-case keywords, one clause per line and indented subqueries, or minify it to one line. Comments and strings are kept. Runs in your browser.

SRI Hash Generator Get the integrity value for a script or stylesheet from pasted text or a picked file, in sha256, sha384 or sha512, and check an existing value.

String Escape and Unescape Escape or unescape text for JSON, JavaScript, HTML attributes, XML, CSV, SQL, regular expressions, C#, Java and shell, with the rules of each format.

Text Shadow Generator Build a CSS text-shadow with several layers, each with its own offsets, blur, colour and opacity. Type your own text, see the preview and copy the CSS.

Text to Binary Converter Convert text to binary, hexadecimal, decimal or octal bytes in UTF-8, and back. Turkish letters and emoji are counted with their real byte lengths.

TOML to JSON Converter Convert a TOML 1.0.0 file to JSON in your browser. Tables, arrays of tables, dates and 64-bit integers keep their exact meaning, and an error names its line.

TOTP Generator Show the current 6 or 8 digit two-factor code from a Base32 secret or otpauth:// URI, with SHA-1, SHA-256, SHA-512, a countdown and HOTP. Nothing is sent.

Two's Complement Calculator Convert a signed number to its two's complement bits in 8, 16, 32 or 64 bits, and back. Compares one's complement and sign-magnitude, and flags overflow.

ULID, UUID v7 and Nanoid Generator Generate ULIDs, UUID v7 and nanoid-style IDs with your own alphabet and length, and read the time in a ULID or UUID v7. Random bits come from your browser.

Unicode Character Inspector Inspect each character: code point, Unicode name, category, block, UTF-8 and UTF-16 bytes, and HTML and JavaScript escapes. Search a name such as snowman.

Unix Timestamp Converter Convert a Unix timestamp in seconds, milliseconds, microseconds or nanoseconds to an ISO date, your local time and a relative time, and back again.

URL Encode and Decode Percent-encode text for a web address, or decode an encoded link to its readable text and query parameters. Runs in your browser, so your links stay private.

URL Parser Split a web address into protocol, host, port, path, query parameters and hash, as the browser reads it. Works offline, and a relative path needs a base.

Username Generator Make random usernames from English, German or Turkish word lists, in CamelCase, with numbers or with separators, within your length limits. Nothing is stored.

UUID Generator Generate UUID version 4, UUID version 7 or ULID identifiers in bulk, in upper or lower case, with braces if needed. Random bits come from your browser.

Wi-Fi Password Generator Make a random Wi-Fi passphrase of 8 to 63 characters, as WPA2 and WPA3 allow, with its entropy in bits. Easy-to-type symbols. Nothing is stored.

X.509 Certificate Decoder Decode a PEM or Base64 X.509 certificate: issuer, subject, validity with the days left, key, usage, names and fingerprints. Read in your browser, not checked.

XML Formatter and Validator Paste XML to indent it or minify it on one line, keep comments and CDATA, and see whether it is well-formed, with the line and column of the first error.

XML to JSON Converter Convert XML to JSON: attributes become @names, text becomes #text, repeated elements become arrays. Checks the XML first. Runs in your browser.

YAML to JSON Converter Convert YAML 1.2 to JSON in your browser. Each error gives its line and column, and a file with several --- documents becomes a JSON array. Nothing is uploaded.

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