Developer tools

Private: nothing leaves your browser

The small utilities you reach for a dozen times a day: format some JSON, decode a token, hash a string, generate an ID, check a regex. Each one is its own page, loads instantly and runs as JavaScript on your device, so payloads and secrets never go to a server.

12 tools

All Dev tools

JSON Formatter Format, validate and minify JSON with clear error positions. Base64 Decode Decode Base64 back to text, with full UTF-8 support. Base64 Encode Encode text or a file to Base64, or to a data URI. JWT Decoder Read a token's header, payload and expiry. Nothing is sent anywhere. URL Decode Decode a percent encoded URL or query value back to plain text. URL Encode Percent encode a value for a query string, or a whole URL. Hash Generator MD5, SHA-1, SHA-256 and SHA-512 checksums of text or files. UUID Generator Generate v4 UUIDs one at a time or a thousand at once. Regex Tester Test a pattern live, see every match and capture group. YAML to JSON Turn a Compose file, pipeline or manifest into JSON, as you type. JSON to YAML Turn JSON into readable YAML, quoting only what has to be quoted. Text Diff Checker Compare two blocks of text side by side and spot every change.

About these tools

Every developer tool here does one job on one page, which means no menus to hunt through and no editor to configure. Paste in what you have, read the result, copy it out.

They all run client side. There is no API call behind the JSON formatter or the JWT decoder, so you can safely paste a production payload, an access token or a config file without it leaving your machine. That also means they stay fast: no round trip, no queue, no rate limit.

A few of these are worth knowing about before you need them. JWT Decoder deliberately will not verify a signature, because doing that would mean asking you to paste a production signing secret into a web page. YAML to JSON follows YAML 1.2, so a country code of NO stays the string NO instead of becoming false, and it names anything it cannot handle rather than quietly dropping it. Hash Generator checks a download against its published checksum without the file going anywhere.

Other categories

PDF tools Image tools Text tools Calculators Generators