Developer tools that stay in your browser

JSON Formatter

Format, validate and beautify JSON directly in your browser.

JSON Validator

Validate JSON and pinpoint the first error with a line, column and plain-English explanation.

JSON Minifier

Compress formatted JSON into a single compact line and see exactly how many bytes you save.

JWT Decoder

Inspect the header, payload and claims of a JSON Web Token - decoded locally, never uploaded.

Regex Tester

Test regex patterns against your text with live highlighting, capture groups and common-pattern shortcuts.

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text, in your browser.

Random String Generator

Generate secure random strings and passwords with control over length and character set.

Base64 Encode & Decode

Convert text to Base64 or decode it back, with an optional URL-safe mode - all in your browser.

URL Encoder / Decoder

Percent-encode text for safe use in URLs and query strings, or decode it back to readable form.

HTML Entity Encoder / Decoder

Convert HTML to its escaped entity form or decode entities back to readable markup.

JSON Diff

Compare two JSON documents and see every added, removed or changed value with its exact path.

JSON to CSV Converter

Convert a JSON array of objects into a CSV file with automatic headers and proper escaping.

CSV to JSON Converter

Convert CSV files into a clean JSON array, with optional automatic type detection.

JSON to TypeScript Converter

Generate TypeScript interfaces or type aliases from a JSON sample, with nested types inferred.

Regex Builder

Compose regular expressions from reusable blocks and watch matches highlight live against your test text.

Text Diff Checker

Line-by-line text comparison that shows every added, removed and unchanged line.

Unix Timestamp Converter

Two-way Unix timestamp conversion between epoch seconds and human-readable dates.

Cron Expression Generator

Assemble a cron expression from field selectors with a live description and next-run preview.