20 free developer tools — format, validate, encode, decode

Format, indent, and pretty-print JSON instantly in your browser.

Validate JSON syntax and pinpoint parse errors line by line.

Pretty-print and indent XML documents with nested elements.

Validate XML well-formedness using the browser's native parser.

Format and indent SQL queries for readability.

Pretty-print HTML markup with consistent indentation.

Strip comments and whitespace to shrink CSS file size.

Expand minified CSS into a readable, indented stylesheet.

Compress JavaScript by removing comments and whitespace.

Reformat minified JavaScript into clean indented code.

Decode JWT header and payload claims safely in your browser.

Encode any UTF-8 text to a Base64 string.

Decode Base64 strings back to readable text.

Generate cryptographically random UUID v4 identifiers.

Create strong random passwords with custom rules.

Test JavaScript regular expressions against sample text live.

Compute SHA-1, SHA-256, SHA-384, and SHA-512 hashes.

Send GET/POST/PUT/PATCH/DELETE requests and inspect responses.

Convert between Unix timestamps and human-readable dates.

Build and understand cron expressions with handy presets.