Free Developer Tools
Twelve tools for the conversions that come up between one system and the next: format or minify JSON, move between JSON and CSV, turn YAML into JSON, encode and decode base64, URLs and HTML entities, decode a JWT and verify its signature, generate v4 or v7 UUIDs, convert number bases, and read a Unix timestamp as a date. It all runs locally, which is what makes it safe to paste a production payload with a live token in it.
Base64 Encoder & Decoder
Encode and decode Base64, including the URL-safe variant, without breaking accents.
Open tool DeveloperCSV to JSON Converter
A real CSV parser: quoted fields, embedded newlines, ragged rows.
Open tool DeveloperHTML Entity Encoder & Decoder
Escape text for HTML, or turn a page full of entities back into readable text.
Open tool DeveloperImage to Base64 Converter
Turn an image into a data URI you can paste straight into CSS or HTML.
Open tool DeveloperJSON Formatter
Pretty-print or minify JSON, with a real line number on errors.
Open tool DeveloperJSON to CSV Converter
Flatten a JSON array into CSV with correct quoting and escaping.
Open tool DeveloperJWT Decoder
Decode a JWT, read its claims, and check the signature locally.
Open tool DeveloperNumber Base Converter
Binary, octal, decimal, hex and any base from 2 to 36, exact at any size.
Open tool DeveloperUnix Timestamp Converter
Epoch seconds or milliseconds to a readable date, and back again.
Open tool DeveloperURL Encoder & Decoder
Percent-encode a value or take a messy URL apart, parameter by parameter.
Open tool DeveloperUUID Generator (v4 and v7)
Generate v4 or time-sortable v7 UUIDs, and take an existing one apart.
Open tool DeveloperYAML to JSON Converter
Turn YAML into JSON, with honest errors instead of silent guesses.
Open toolAll categories
Merge, split, rotate and reorder PDF pages without the file leaving your computer.
See these 6 toolsImages
Six tools for making an image lighter, smaller, a different format — or for reading what it hides.
See these 11 toolsText
Eleven tools for a block of text you need to change: case, order, duplicates, differences, counts.
See these 8 toolsDesign
Eight tools for the numbers behind a design: color formats, palettes, contrast, gradients, shadows, units.
See these 5 toolsSecurity
Five tools for passwords, hashes and 2FA codes, none of which send anything to a server.
See these 9 toolsCalculators
Nine calculators for arithmetic people get wrong on a phone: percentages, discounts, VAT, tips, loans.
See these 3 toolsEveryday
Three small tools that fit nowhere else: exact age, a fair random draw, Roman numerals.
See these 4 toolsTime
Four tools for counting time: days between dates, a week of shifts, a countdown, a focus timer.
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