Developer
Encoders, formatters, generators, and converters for everyday developer tasks — all client-side.
JSON Formatter & Validator
Beautify, minify and validate JSON — a collapsible tree view, syntax errors by line and column, any indent width or tabs, sort keys, and download.
DeveloperBase Encoder — Base64, Base32, Base58, Ascii85 & Z85
Encode and decode text or any file with Base64, Base32, Base58, Base64URL, Ascii85 or Z85 — five character sets, 76-char MIME lines, per-line mode.
DeveloperURL Encoder & Decoder
Percent-encode text for safe use in URLs, or decode an encoded URL back to readable text. Free, in your browser.
DeveloperHash Generator (MD5 & SHA)
Hash text or a file as you type — 14 digests including MD5, SHA-256, SHA-3 and BLAKE3, plus HMAC, 7 input encodings and checksum verify. In your browser.
DeveloperID Generator — UUID, NanoID, ULID, ObjectID & MAC
Ten ID types — UUID v1/v3/v4/v5/v7, nil, NanoID, ULID, ObjectID, MAC — up to 1,000 at a time, with GUID styling and a UUID validator. Free, in your browser.
DeveloperJSON to CSV Converter
Convert a JSON array of objects to CSV, or CSV back to JSON — quoting handled correctly. Free, in your browser.
DeveloperPassword Generator
Generate strong random passwords or memorable word passphrases in your browser. Free, nothing sent anywhere.
DeveloperJWT Decoder
Decode a JWT and verify its HMAC or RSA/ECDSA signature with your secret or public key, plus a live expiry countdown. Token and keys never leave your device.
DeveloperUnix Timestamp Converter
Convert Unix (s/ms/µs/ns), Windows FILETIME, Mongo ObjectID and Excel serials to dates in any time zone, and back. Live epoch clock. Free, in-browser.
DeveloperQR Code Generator
Create a QR code for a URL, Wi-Fi, contact, email, SMS, phone, location, PayPal or SEPA transfer — dot and corner shapes, a center logo, PNG or SVG. Free.
DeveloperRegex Tester
Test a regex live — 7 flags, group offsets, a plain-English explanation, test cases, a share link and code for 8 languages. Free, in your browser.
DeveloperMarkdown to HTML
Convert Markdown to clean HTML with a live preview and one-click copy. Free, safe, in your browser.
DeveloperHTML Entity Encoder / Decoder
Encode text to HTML entities or decode entities back to text — named, decimal and hex. Free, in your browser.
DeveloperJSON to Code — TypeScript, Go, Rust, Python & more
Paste JSON and generate type definitions in TypeScript, Go, Rust, Python, Java, Kotlin, Swift or C# — pick the language from a dropdown. Free, no upload.
DeveloperCron Expression Explainer
Explain any cron expression in plain English and preview its next runs, or build one from five fields — free, no upload, in your browser.
DeveloperText Encrypt & Decrypt (AES)
Encrypt and decrypt text with a password using AES-256-GCM — entirely in your browser, nothing is ever uploaded.
DeveloperText to Binary
Convert text to binary, hexadecimal, decimal or octal and back — instantly and privately, using UTF-8 so any character round-trips.
DeveloperString Escape / Unescape
Escape text for source code (newlines, tabs, quotes, backslashes, \uXXXX) and unescape it back — instantly, in your browser.
DeveloperURL Parser
Break a URL into protocol, host, port, path, fragment and a table of query parameters — instantly and privately.
DeveloperHTTP Status Codes
A searchable reference of HTTP status codes — 200, 301, 404, 500 and more — with plain-language meanings. In your browser.
Developer3D Tiles Viewer & Georeferencer (move + save tileset.json)
View a 3D Tiles model (tileset.json + b3dm), move it to the right WGS84 coordinates, two-point align it and save the new tileset.json. Free, in your browser.
DeveloperBitwise Calculator (AND, OR, XOR, NOT, Shift)
Compute AND, OR, XOR, NAND, NOR, XNOR, NOT, shifts and rotates on two 32-bit integers — result in decimal, hex, octal and binary, 100% in your browser.
DeveloperASCII Table
Searchable ASCII table (codes 0–127) with decimal, hex, binary, and the character or control-code name — runs 100% in your browser with no upload.
DeveloperCSV to Markdown Table
Convert CSV data into a clean GitHub-flavored Markdown table with header and delimiter options — runs 100% in your browser with no upload.
DeveloperHTML to Text Converter (Strip HTML Tags)
Paste HTML and instantly get clean plain text with tags removed, entities decoded and line breaks preserved — runs 100% in your browser, nothing is uploaded.
DeveloperPassword Strength & Entropy Checker
Check how strong a password is — its entropy in bits, a Very weak to Very strong rating, and the character sets it uses. Free, no upload, in your browser.
DeveloperUnicode Character Inspector
Break text into Unicode code points and see the U+ codepoint, decimal, UTF-8 bytes, HTML entity and Unicode block of every character. Free, in your browser.
DeveloperHMAC Generator (SHA-256, SHA-512, SHA3-256, MD5 and more)
Generate an HMAC with a secret key across nine hashes — SHA-256, SHA-512, SHA3, MD5, RIPEMD-160 — as hex, Base64, Base64URL or binary. 100% in your browser.
DeveloperIP Subnet Calculator (IPv4 CIDR)
Enter an IPv4 CIDR like 192.168.1.10/24 and get the network, broadcast, host range, subnet mask, wildcard mask and host count. Free, in your browser.
DeveloperLine Numberer
Add sequential line numbers to any text with custom start, separator, and zero-padding — runs 100% in your browser with no upload.
DeveloperMIME Type Lookup
Look up the MIME type for a file extension, or the extension for a content type, in a searchable table of common web, image, audio, video and font types.
DeveloperQuery String Builder
Build a properly URL-encoded query string from key/value pairs, with an optional base URL — runs 100% in your browser, nothing is uploaded.
DeveloperUTM Builder — Campaign URL Tracking Link Generator (free, no sign-up)
Build UTM campaign tracking links for GA4, email and social — source/medium presets, lowercase cleanup, bulk generation and a QR code. Free, in your browser.
DeveloperIBAN Validator & Formatter — Check an International Bank Account Number (free, no upload)
Validate any IBAN with the ISO 13616 mod-97 checksum and country length rules, see which country it belongs to, and format it in groups of four. No upload.
DeveloperMarkdown Table Generator
Build a GitHub-flavored Markdown table in a visual grid — add rows and columns, type the cells, set per-column alignment, and copy it. Free, in your browser.
DeveloperHTML Minifier
Minify HTML to shrink page size — comments stripped and whitespace collapsed, while pre, script, style and conditional comments are kept. Free, no upload.
DeveloperSVG to JSX Converter
Convert an SVG icon or any HTML snippet to JSX — camelCased attributes, inline styles as a style object, optional component wrapper. Free, in your browser.
DeveloperJavaScript Keycode Info — event.key, code & keyCode Inspector
Press any key to see its JavaScript event.key, event.code, keyCode, which, location and modifier flags — a keycode.info-style inspector, in your browser.
Developerbcrypt Hash Generator & Password Verifier (free, no upload)
Hash a password with bcrypt at the cost factor you pick, and verify a password against an existing $2a$/$2b$/$2y$ hash. Free, no upload, in your browser.
DeveloperUser-Agent Parser — Decode Browser, OS & Device from a UA String (free)
Decode any User-Agent string into browser, OS, device, engine and CPU details — prefilled with your own UA, with copy-as-JSON. Free, in your browser.
DeveloperRSA Key Pair Generator (2048/4096)
Generate an RSA public/private key pair in PEM format — runs 100% in your browser with the Web Crypto API, nothing is uploaded.
DeveloperTOTP / 2FA Code Generator
Generate live TOTP two-factor codes (RFC 6238) from a Base32 secret, with a countdown and an otpauth:// enrollment QR. Free, no upload, in your browser.
DeveloperDocker Run to Compose — Convert a docker run Command to docker-compose.yml (free, no upload)
Convert a docker run command into an equivalent docker-compose.yml — ports, volumes, env vars, name, restart, network and workdir. Free, in your browser.
DeveloperChmod Permission Calculator
Convert Unix file permissions between symbolic (rwxr-xr--) and octal (754) with a live checkbox grid — runs 100% in your browser with no upload.
DeveloperJSON Diff
Compare two JSON documents and see every added, removed and changed key with its full path, optionally ignoring array order — 100% in your browser, no upload.
DeveloperPunycode Converter (IDN ⇆ xn--)
Convert internationalized domain names between Unicode and Punycode (the xn-- ASCII form) in both directions — runs 100% in your browser, no upload.
DeveloperHex Dump
Turn any text or file into an xxd-style hex dump with byte offsets, hex bytes and an ASCII gutter — and decode one back. Free, in your browser.
DeveloperJSON to XML Converter
Convert JSON into clean, indented XML with a live preview and one-click copy — runs 100% in your browser with no upload.
DeveloperData Extractor — Pull Emails, URLs & More from Text
Extract emails, URLs, domains, IPs, MAC addresses, dates, phones, hashtags, mentions, file paths or hashes from any text. Free, in your browser, no upload.
DeveloperDelimiter Converter
Convert tabular text between comma, tab, semicolon, pipe, space and new-line delimiters, or any separator you type, with a live preview. No upload.
DeveloperMeta Tags Generator
Generate SEO, Open Graph and Twitter Card meta tags — 12 page types, image and account properties, and a preview of the card as six sites will draw it.
Developerrobots.txt Generator — Build a Crawler Rules File Online
Generate a valid robots.txt file with User-agent, Allow, Disallow, Crawl-delay and Sitemap directives — runs 100% in your browser, no upload, no sign-up.
DeveloperSQL IN Clause Generator
Paste a list of values, one per line, and build a SQL IN (...) or NOT IN (...) clause — with quoting, a column name, and long lists split into groups of 1,000.
DeveloperCSV to SQL INSERT Generator
Paste CSV and instantly build SQL INSERT statements with a table name, header, and delimiter options — runs 100% in your browser with no upload.
Developer.env to JSON Converter
Convert a .env file to JSON and back with two live, editable boxes — runs 100% in your browser with no upload.
DeveloperMarkdown Table of Contents Generator
Generate a nested Markdown table of contents with anchor links from your headings instantly — runs 100% in your browser with no upload.
Developercurl Command Builder
Build a ready-to-run curl command from a method, URL, headers and body — runs 100% in your browser, nothing is uploaded.
DeveloperJWT Generator (HS256/384/512)
Create a signed HMAC JWT from a JSON payload and secret — runs 100% in your browser, nothing is uploaded.
DeveloperJSON Flatten & Unflatten
Flatten nested JSON into dot/bracket key paths and rebuild it back, with a live two-way preview — runs 100% in your browser with no upload.
DeveloperTwo's Complement Converter (8/16/32-bit Binary & Hex)
Convert a signed integer to its two’s complement binary and hex at 8, 16 or 32 bits, and decode a bit pattern back to signed decimal. Free, no upload.
DeveloperGray Code Converter (Decimal ⇄ Binary ⇄ Gray Code)
Convert between decimal, binary and Gray code with instant three-way boxes — runs 100% in your browser, nothing is uploaded.
DeveloperINI to JSON Converter
Convert INI config files into clean JSON with a live preview and one-click copy — runs 100% in your browser with no upload.
DeveloperResistor Color Code Calculator
Pick the color of each band on a 4- or 5-band resistor and instantly read its resistance in ohms plus tolerance — runs 100% in your browser with no upload.
DeveloperCSS Minifier
Minify CSS to shrink file size — strips comments and whitespace and collapses rules, running 100% in your browser with no upload.
DeveloperISBN Validator (ISBN-10 & ISBN-13)
Check whether a book's ISBN-10 or ISBN-13 has a correct checksum and instantly see which standard it is — runs 100% in your browser, nothing is uploaded.
DeveloperLuhn Checker & Check Digit Calculator
Validate a card, IMEI or account number with the Luhn checksum and compute its check digit — runs 100% in your browser, no upload.
DeveloperBBCode to HTML Converter
Convert BBCode markup to clean HTML instantly — runs 100% in your browser with no upload and no sign-up.
DeveloperJSONL to JSON Array Converter
Convert JSON Lines (NDJSON) to a pretty JSON array and back, two ways, live as you type — runs 100% in your browser with no upload.
DeveloperSemver Checker & Version Comparator
Parse a semantic version into its major, minor, patch, prerelease and build parts and compare two versions by precedence. Free, in your browser, no signup.
DeveloperYAML ⇄ JSON Converter
Convert YAML to JSON, JSON to YAML, or YAML to XML or CSV — open a file or load a URL, choose the indent. 100% in your browser, no upload.
DeveloperSQL Formatter & Beautifier
Beautify or minify SQL in 20 dialects — keyword and identifier case, indent width and style, comment removal, Python/PHP string output. All in your browser.
DeveloperHTML Formatter & Minifier
Beautify HTML with clean indentation or minify it to one compact line — pre and textarea preserved, inline JS/CSS re-indented or left alone. Free, no upload.
DeveloperXML Formatter
Beautify, minify or validate XML at any indent from 0 to 10 spaces or a tab — paste, format, copy. 100% in your browser, no upload.
DeveloperBarcode Generator
Generate barcodes in 15 symbologies — Code 128, EAN/UPC, Code 39, ITF-14, MSI, Pharmacode, Codabar. Download as PNG or SVG. 100% in your browser, no upload.
DeveloperJavaScript Beautifier
Pretty-print minified JavaScript or JSON: 1–10 space or tab indent, four brace styles, line wrapping, JSX. 100% in your browser, no upload.
DeveloperXPath Tester
Evaluate an XPath expression against pasted XML or HTML and list every matching node — 100% in your browser, no upload.
DeveloperJSON Repair
Fix broken JSON — trailing commas, comments, single quotes, unquoted keys — 100% in your browser, no upload
DeveloperJavaScript Minifier
Minify and compress JavaScript with Terser — 100% in your browser, no upload
DeveloperJSON Schema Generator
Infer a JSON Schema from a sample JSON payload — draft 2020-12 or draft-07, with automatic string format detection — 100% in your browser, no upload
DeveloperMock Data Generator
Generate rows of fake data — names, emails, cities, UUIDs, dates — as JSON, CSV or SQL for seeding a database or stubbing an API. Free, no upload.
Developercurl to Code Converter
Convert a curl command into ready-to-run fetch, Node.js, Python, Go, or PHP code — 100% in your browser, no upload
DeveloperSitemap.xml Generator — Build a Sitemap From a URL List
Generate a valid sitemap.xml from a list of URLs, apply an optional default changefreq and priority, then copy or download it — 100% in your browser, no upload
DeveloperHTTP Basic Auth Header Generator & Decoder (free, no upload)
Turn a username and password into an Authorization: Basic header and Base64 token, or decode a header back into credentials. UTF-8 safe, free, no upload.
DeveloperBIP39 Mnemonic Generator and Validator
Generate and validate BIP39 mnemonic seed phrases of 12 to 24 words, with crypto-strong randomness and full checksum checking. Free, in your browser.
DeveloperIP Address Converter (IPv4 & IPv6)
Convert one IP address between dotted-decimal, integer, hex, binary and IPv4-mapped IPv6 — plus IPv6 expand/compress — 100% in your browser, no upload
DeveloperYAML Formatter & Validator
Format, validate and pretty-print YAML at any indent from 1 to 10 spaces, with optional key sorting and line-numbered errors. Comments kept, output stays YAML.
DeveloperDevice Info — Live Screen, Browser, OS & System Readout
See a live readout of your own device — screen resolution, viewport, pixel ratio, CPU cores, memory, browser, OS and time zone. Free, nothing is uploaded.
DeveloperURL & IP Defanger and Refanger
Defang and refang URLs, domains, IP addresses and emails for safe IOC sharing — http becomes hxxp and every dot becomes [.], or reverse it. Free, no upload.
DeveloperShannon Entropy Calculator
Measure the Shannon entropy in bits per byte of any text or dropped file — a reading of 7.5 or above suggests encrypted or compressed data. Free, no upload.
DeveloperXOR Cipher — Encrypt, Decrypt & Single-Byte Brute Force
XOR text or hex against a repeating key, see the result as hex and printable text, and crack single-byte XOR with a brute-force ranker. Free, no upload.
DeveloperEmail Normalizer
Canonicalize email addresses — strip Gmail dots and +tags, fold googlemail to gmail, and collapse duplicate contacts — 100% in your browser, no upload
DeveloperSafeLink Decoder — Unwrap Outlook SafeLinks & Proofpoint URLs
Unwrap Outlook SafeLinks and Proofpoint URL Defense links to the real destination — paste one link or a whole email body. Free, no upload, in your browser.
DeveloperIPv6 ULA Generator (RFC 4193)
Generate a random RFC 4193 IPv6 unique local address /48 prefix with a crypto-strong Global ID, plus an example /64 subnet and host. Free, no upload.
DeveloperIP Range to CIDR Converter
Convert an IPv4 start-end range into the smallest set of CIDR blocks that covers it, and expand any CIDR back to its first and last address and count.
DeveloperGit Cheat Sheet
Searchable reference of the Git commands you forget — commit, branch, merge, rebase, stash and undo — in plain language with one-click copy. Free, no signup.
DeveloperRegex Cheat Sheet
A searchable regex cheat sheet with copy-ready examples for anchors, character classes, quantifiers, groups, lookaround and flags. Free, in your browser.
DeveloperDiscord Timestamp Generator
Turn any date and time into Discord dynamic timestamp markup in all seven styles, each with a live preview and one-click copy — 100% in your browser, no upload
DeveloperRandom Port Generator
Generate a random port number in the default 1024–65535 range or a custom range, plus well-known ports to avoid — 100% in your browser, no upload
DeveloperJSON Schema Validator
Validate a JSON document against a JSON Schema and see every violation with its exact path — draft-07 and 2020-12 supported. Free, in your browser, no upload.
DeveloperJSONPath Tester
Run a JSONPath expression against pasted JSON and list every matching value with a count — 100% in your browser, no upload.
DeveloperX.509 Certificate Decoder
Decode a PEM X.509 or SSL/TLS certificate — subject, issuer, validity, SAN, key usage, signature algorithm and SHA-256 fingerprint. Free, no upload.
DeveloperFile Type Detector — Identify Files by Magic Bytes
Identify a file by its magic bytes — find the real format even when the extension is wrong or missing, and get warned on mismatches. Free, no upload.
DeveloperProtobuf Decoder
Decode a raw protobuf message from hex or base64 with no .proto schema — field numbers, wire types, strings and nested sub-messages. Free, no upload.
DeveloperBinary Strings Extractor
Extract printable ASCII and UTF-16 strings from any binary, firmware or malware sample — like the Unix strings command, with a length filter. Free, no upload.
DeveloperPhone Number Formatter & Validator — E.164, National & International (free)
Parse and validate a phone number, then format it as E.164, national, international and RFC3966 tel: URI, with country and line type — no upload
DeveloperWYSIWYG HTML Editor
Write rich text in a visual editor and get clean, safe HTML — bold, italic, headings, lists and links, with scripts and inline styles stripped. No upload.
DeveloperXSD Validator
Validate an XML document against an XSD schema and list every violation with its line number, using the real libxml2 engine. Free, no upload.
DeveloperMAC Address Vendor Lookup
Look up the hardware vendor behind any MAC address in the bundled IEEE OUI registry, or search the registry by company name. Free, in your browser, no upload.
DeveloperEC / ECDSA Key Pair Generator (P-256, secp256k1, Ed25519)
Generate an EC key pair on nine curves — P-256, secp256k1, brainpool, SM2, Ed25519 — as PEM, JWK, OpenSSH or raw bytes, optionally encrypted. Free, no upload.
DeveloperJWK to PEM Converter — RSA & EC, Both Directions
Convert keys between JWK and PEM (SPKI / PKCS#8) in both directions, for RSA and EC — handy when wiring up JWT, OIDC and JWKS. Free, no upload.
DeveloperMAC Address Generator
Generate random MAC addresses in bulk — pick the separator, the case, a fixed 1–5 octet prefix, and the unicast and locally-administered bits. Free, no upload.
DeveloperCBOR Decoder & Encoder
Decode CBOR from hex or base64 into readable JSON and encode JSON back to canonical CBOR hex — for WebAuthn, COSE and IoT payloads. Free, no upload.
DeveloperCSR Decoder — Inspect a PKCS#10 Certificate Signing Request
Decode a PEM or Base64 CSR (PKCS#10) to read its subject DN, subject alternative names, key algorithm and size, and signature algorithm. Free, no upload.
DeveloperArgon2 Password Hash Generator & Verifier (free, no upload)
Hash a password with Argon2id, Argon2i or Argon2d at your own memory, time and parallelism cost, or verify one against an existing hash. Free, in your browser.
DeveloperPGP Encryption Tool — Generate Keys, Encrypt, Decrypt, Sign and Verify
Generate an OpenPGP key pair (Curve25519 or RSA), encrypt and decrypt messages, and sign or verify a signature. Free, in your browser, no upload.
Developer.gitignore Generator
Build a .gitignore from common stack, OS and editor templates — 100% in your browser.
DeveloperJSON to Zod Schema
Turn a sample JSON object into a Zod schema with an inferred TypeScript type — 100% in your browser.
DeveloperHTML to JSX Converter
Convert HTML into React/Preact JSX — class→className, style objects, self-closed tags. 100% in your browser.
DeveloperSmart Decode (Magic Decoder)
Auto-detect and decode Base64, hex, URL-encoding, JWT or HTML entities — layer by layer, 100% in your browser.
The largest group here, so by job rather than by name. Reading something opaque: decode a JWT, an X.509 certificate, a protobuf message, a data URL, a defanged URL or a safelink; work out what a file actually is from its bytes. Making something correct: format or repair JSON, YAML and XML, test a regex, test an XPath or JSONPath, check a JSON Schema, read a cron expression back in plain words.
Generating: UUIDs and other IDs, passwords, TOTP codes, BIP39 mnemonics, mock data, QR and barcodes, sitemaps, basic-auth headers. Converting: JSON to CSV or to typed code in eight languages, curl to code, timestamps, IP notations, character encodings, text to binary.
One thing to be clear about, because it matters for what you are willing to paste: everything here runs in your browser. The JWT decoder does not send your token anywhere; the hash generator hashes locally; the password generator uses your browser's own cryptographic random source. That is the reason to use these rather than the first search result — a token or an internal payload pasted into a server-side tool is a token you have to rotate.