All tools

52 developer tools, grouped by category. Every client tool runs entirely in your browser.

Formatters & Validators

JSON Formatter & ValidatorFormat, validate and minify JSON in your browser. Pretty-print with 2/4-space or tab indent, sort keys, and get parse errors with the exact line and column.SQL FormatterFormat and beautify SQL queries online with dialect-aware indentation for PostgreSQL, MySQL, SQL Server, BigQuery and more. Runs in your browser.HTML FormatterBeautify or minify HTML in your browser. Re-indent messy markup or strip comments and whitespace to shrink payloads. Private, offline, and instant.CSS Beautifier & MinifierMinify CSS online to shrink file size, or beautify messy stylesheets into readable, indented rules. Runs entirely in your browser — nothing is uploaded.JavaScript Beautifier & MinifierBeautify or minify JavaScript in your browser. Re-indent messy code or strip comments and whitespace, with a scanner that understands strings and regex.JSON DiffCompare two JSON documents structurally and see every added, removed, and changed value by path. Ignores key order and formatting. Private and in-browser.XML FormatterFormat and beautify XML in your browser, or minify it to one line. Indent nested tags, keep comments and CDATA intact, and flag mismatched tags. No upload.

Encoders & Decoders

Base64 Encode / DecodeEncode and decode Base64 in your browser with full UTF-8 support and the URL-safe alphabet. Text is converted entirely on your device — nothing is uploaded.JWT DecoderDecode a JWT to read its header and payload without sending it anywhere. See the algorithm, expiry and issued-at times — and why decoding is not verifying.URL Encode / DecodeFree, private URL encoder and decoder that runs entirely in your browser. Percent-encode query values or whole URLs and decode %-escapes instantly.HTML Entity Encode / DecodeEncode and decode HTML entities in your browser — escape <, >, & and quotes, or turn named and numeric references back into text. Private, free, no upload.Base32 Encode / DecodeEncode and decode RFC 4648 Base32 in your browser with full UTF-8 support. Case-insensitive decoding that ignores whitespace, ideal for TOTP and 2FA secrets.

Converters

CSV to JSON ConverterConvert CSV to JSON in your browser: RFC 4180 quoting, custom delimiters, and header-to-object mapping. Private and offline — your data never leaves the page.YAML ⇄ JSON ConverterConvert YAML to JSON and JSON to YAML instantly in your browser. Free, private, and offline-capable, with clear parse-error reporting and no uploads.JSON to TypeScriptGenerate TypeScript interfaces from any JSON in your browser: nested objects, arrays, union types, optional keys, and null-aware fields. Private, no uploads.JSON to CSV ConverterConvert a JSON array of objects to CSV with RFC 4180 quoting, custom delimiters, unioned columns, and JSON-stringified nested values. Private, no uploads.Number Base ConverterConvert numbers between any base from 2 to 36 — binary, octal, decimal, hex — using BigInt for exact arbitrary-size values. Private, in-browser, no uploads.Roman Numeral ConverterConvert Roman numerals to numbers and integers to Roman numerals in your browser. Auto-detects the direction and validates canonical form, from 1 to 3999.

Generators

UUID Generator (v4 / v7)Generate random v4 and time-ordered v7 UUIDs online, free and private. IDs are created in your browser with a CSPRNG and never sent anywhere.Password GeneratorGenerate strong, random passwords in your browser with adjustable length, character sets, and a live entropy readout. Private and offline, nothing is sent.Lorem Ipsum GeneratorGenerate lorem ipsum placeholder text by paragraphs, sentences, or words. Free, private, and fully in-browser — copy classic filler for mockups instantly.Hash Generator (MD5/SHA-1/256/512)Generate MD5, SHA-1, SHA-256 and SHA-512 hashes from text in your browser. See all four digests at once, computed locally so nothing is uploaded.QR Code GeneratorGenerate QR codes from any URL or text in your browser, free and private. Tune error correction and download a crisp, scalable SVG — nothing is uploaded.Slug GeneratorTurn any title or heading into a clean, URL-safe slug. Strips accents and punctuation, collapses spaces to hyphens, and runs entirely in your browser.NanoID GeneratorGenerate short, URL-friendly NanoIDs online with a secure random source. Set the size, count, and alphabet, then copy compact unique IDs, all in-browser.Random Number GeneratorGenerate random numbers online in any range with a cryptographic RNG. Pick integers or decimals, unique sets, and bulk counts, computed in your browser.Meta Tag GeneratorGenerate SEO meta tags, Open Graph, and Twitter card markup from a title, description, and image. HTML-escaped output you can paste, all in-browser.

Text Tools

Case ConverterConvert text between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE and dot.case. Free, private, and runs entirely in your browser.Word & Character CounterCount words, characters, sentences, paragraphs, and reading time instantly. A free, private word & character counter that runs entirely in your browser.Line Sorter & DeduplicatorSort lines alphabetically or numerically and remove duplicate or blank lines, right in your browser. Case-insensitive, locale-aware, and fully private.Text Diff CheckerCompare two blocks of text or code online and see added, removed, and unchanged lines instantly. A free, private line diff that runs in your browser.Markdown PreviewPreview Markdown online with a live GitHub-flavored renderer. Tables, code blocks, and task lists render instantly and privately in your browser.Whitespace CleanerClean messy whitespace online: collapse repeated spaces, trim lines, remove blank lines, expand tabs, and strip non-breaking spaces. Private, in-browser.String Length CalculatorMeasure string length by Unicode code points, UTF-16 units, and UTF-8 bytes, plus words, lines, and graphemes. Emoji-aware and runs in your browser.Reverse TextReverse text by characters, words, or lines online. The character reverse is emoji-safe, so surrogate pairs stay intact. Free, private, and in your browser.Find and Replace TextFind and replace text online with literal or regex search, case-insensitive matching, and $1 capture groups. Replace all or the first match, privately.

Crypto & Security

Regex Tester & DebuggerTest and debug regular expressions online in your browser. See every match, numbered and named capture groups, and flag toggles — private, nothing uploaded.ROT13 & ROT47 Encoder / DecoderEncode and decode text with the ROT13 and ROT47 ciphers, live in your browser. Each is its own inverse, so one click scrambles and unscrambles. Fully private.HMAC GeneratorGenerate an HMAC for a message and secret key with SHA-1, SHA-256, SHA-384, or SHA-512. Lowercase hex, computed locally via Web Crypto and never uploaded.

Date & Time

Unix Timestamp ConverterConvert a Unix epoch timestamp to a human date (and back) with ISO 8601, UTC, and local time. Auto-detects seconds vs milliseconds, fully in-browser.Cron Expression GeneratorBuild a cron expression from presets or your own edits and preview the next five run times in your local timezone. Runs entirely in your browser.Age CalculatorCalculate exact age in years, months, and days from a birth date to today, plus total days, weeks, and days until the next birthday. Private and in-browser.Timezone ConverterConvert a date and time between any two IANA time zones with correct daylight-saving handling. Reads the wall clock in the source zone. Runs in your browser.

CSS & Design

Color ConverterConvert colors between HEX, RGB and HSL in your browser with a live swatch. Handles alpha, #RGB shorthand and rgb()/hsl() syntax — private and free.CSS Box Shadow GeneratorGenerate CSS box-shadow code with a live preview. Set offset, blur, spread, color and inset with sliders, then copy the ready-to-paste declaration.CSS Gradient GeneratorBuild CSS linear and radial gradients with a live preview. Add color stops, set the angle, and copy the ready-to-use background declaration instantly.

Web & Network

DNS LookupLook up DNS records for any domain — A, AAAA, MX, TXT, NS, CNAME and SOA. Runs on our server so it works even behind a locked-down or private network.SSL Certificate CheckerCheck a site's SSL/TLS certificate from our server: expiry date, days remaining, issuer, subject and the SAN list — even for expired or self-signed certs.HTTP Header CheckerCheck the HTTP response headers of any URL: see the status, cache and cookie rules, plus security headers like HSTS, CSP, and nosniff. Server-side lookup.URL Metadata / OG PreviewPreview the Open Graph card Slack, Discord, and social sites build from a URL. Our server fetches the page and reads its og:title, og:image, and meta tags.What Is My IPSee the public IP address the internet uses to reach you, not your private LAN address, plus your user-agent and any proxy chain. A server-side lookup.URL Parser & Query InspectorBreak any URL into its parts — protocol, host, port, path, query and hash — and decode every query parameter. Runs privately in your browser, no upload.