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Developer Tools

Formatters, encoders, hashes and generators for everyday work. 20 free tools, each one showing the math behind its answer and running entirely in your browser.

Developer pages cover the boring parts of the day: JSON formatting and validation, Base64, JWT decoding, hashing, cron expressions, CSS and JavaScript minifiers, regular expression testing, UUID and barcode generation, and Unix timestamps.

Each one shows the exact input it used and the output it produced, so a transformation can be diffed rather than trusted, and each says what it deliberately will not do: a JWT decoder that does not verify a signature, a formatter that does not repair invalid input, a hash that is not a password store.

Everything runs locally, which matters most here: tokens, keys and payloads pasted into these pages never leave the tab.

All 20 Developer Tools tools

Base64 Encoder & DecoderEncode text to base64 or decode it back, in your browser, with the standard and URL-safe alphabets, UTF-8 handled properly, percent-encoding and data URLs too.Encode or decode Base64 →
Color ConverterConvert between hex, rgb() and hsl() in your browser: paste one color, get all three formats and an sRGB channel preview.Convert hex, rgb and hsl →
Cron Expression GeneratorTurn a cron expression into plain English and the next run times: five fields or six, Vixie or Quartz, in any time zone, with the traps named. No upload.Build a cron expression →
Cron to TextTurn a cron expression into plain English: when it runs, how often, and which dialect reads it. Five-field, six-field and Quartz supported. No upload.Read a cron schedule →
CSV to JSON ConverterTurn CSV into JSON in your browser. Quoted fields, semicolons, ragged rows and numbers that are not numbers are handled the RFC 4180 way. Paste and download.Convert CSV to JSON →
Hash GeneratorHash any text with MD5, SHA-1 and SHA-256 in your browser. All three digests at once, copy or download them, and know when to use which. Nothing is uploaded.Hash your text →
HTML Formatter & MinifierMinify or beautify HTML in your browser. Comments and safe whitespace go, while pre, textarea, script and style are copied word for word. Nothing is uploaded.Format or minify HTML →
HTTP Status ReferenceEvery HTTP status code from 100 to 511 in one page: what it means, which class it belongs to, and what to check next. Search by number or by name. Free.Look up a status code →
JavaScript MinifierMinify JavaScript safely in your browser: comments stripped, run whitespace collapsed, identifiers and line breaks never renamed or dropped. No upload.Minify JavaScript →
JSON Formatter & ValidatorPaste JSON and get it formatted, minified or sorted, with the line and column when it is broken plus hints for the four mistakes everyone makes. No upload.Format and validate JSON →
JSON to CSV ConverterTurn a JSON array into a CSV table, or a CSV table into JSON, in your browser. Quotes, other delimiters, ragged rows and formulas handled. Nothing uploaded.Convert JSON to CSV →
JWT Decoder & Hash GeneratorDecode a JSON Web Token and see what every claim means, check an HS256 signature against a secret, and hash text with SHA-256, SHA-1 or MD5 in the browser.Decode a JWT →
Minifier & BeautifierMinify or beautify CSS and HTML in your browser: comments, whitespace and two safe shortenings, with an honest list of what it will not touch. No upload.Minify or beautify code →
Open Graph Preview & SitemapRead a page the way a crawler does: the search result, the share card and a 20-point metadata checklist, plus sitemap.xml and robots.txt builders. No upload.Preview social links →
Regex Tester & ReplacerTest a JavaScript regular expression against your own text: every match with its groups and positions, what each flag does, and how it runs in Python or PCRE.Test a regex →
SQL FormatterFormat SQL in your browser: one clause per line, quoted strings and identifiers copied verbatim, recognized keywords recased on request. Nothing is uploaded.Format SQL →
Unix Timestamp ConverterConvert Unix timestamps to dates and back in your browser: seconds, milliseconds, microseconds, ISO 8601, RFC 2822 and any time zone, with no upload.Convert a Unix timestamp →
URL Encoder & DecoderEncode or decode percent-encoding for a query value, a whole URL or form data - with the scope applied shown, not guessed.Encode or decode a URL →
UUID & Random String GeneratorGenerate version 4 and version 7 UUIDs and random strings in your browser, and check UUIDs you already have: version, variant, timestamp and MAC address.Generate UUIDs →
YAML to JSON ConverterConvert YAML config blocks to JSON in your browser, and back. Reads the YAML that config files use, refusing anchors, aliases and tags by name at the broken line. No upload.Convert YAML to JSON →

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