Free Online Developer Tools
Everyday developer utilities that run entirely in your browser, so it is safe to paste real API responses, tokens and config. No signup, no uploads.
JSON Formatter & ValidatorFormat, beautify, validate and minify JSON online. Colour-coded keys and values, error line numbers, sort keys. Runs in your browser, nothing is uploaded.JWT DecoderDecode a JWT token online and read its header, payload and expiry time. Runs locally in your browser, so your token is never sent anywhere.Base64 Encode / DecodeEncode text to Base64 or decode Base64 to text online. Handles UTF-8, emoji and URL-safe Base64. Private, runs in your browser.Unix Timestamp ConverterConvert Unix timestamps to readable dates and dates to epoch time. Supports seconds and milliseconds, UTC, ISO 8601 and local time.URL Encode / DecodePercent-encode text for URLs or decode %20 style strings. Separate options for query values and full URLs. Free, private, in your browser.Regex TesterTest regular expressions online with live match highlighting, capture groups and flags. Uses the JavaScript regex engine. Free and private.UUID GeneratorGenerate random UUID v4 values in bulk, with or without hyphens, in upper or lower case. Uses your browser secure random generator.Diff CheckerCompare two texts or code snippets and see added and removed lines highlighted. Free online diff tool that never uploads your text.Cron Expression GeneratorBuild and explain cron expressions in plain English and see the next run times. Presets for every minute, hourly, daily and weekdays.Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from text instantly. Computed in your browser, nothing is uploaded.