11 tools, free

Developer tools

Format and compare JSON, convert CSV, encode text, test regex, generate UUIDs, convert timestamps and minify CSS or JavaScript. Tools run locally in your browser with no sign-up.

JSON FormatterFormat, validate and minify JSON without changing number literals.
JSON to CSV ConverterConvert JSON records to CSV or CSV rows to JSON with a table preview.
Base64 Encoder and DecoderEncode UTF-8 text or decode standard Base64 and Base64URL safely.
URL Encoder and DecoderEncode URL components, decode values or inspect repeated query parameters.
HTML Entity Encoder and DecoderEncode HTML special characters or decode named and numeric entities.
UUID GeneratorGenerate one or many random UUID v4 identifiers in your browser.
Unix Timestamp ConverterConvert Unix seconds or milliseconds to dates and dates to timestamps.
Regex TesterTest JavaScript regular expressions with highlighted matches and capture groups.
JSON CompareCompare JSON values and missing keys without rounding large numbers.
CSS MinifierMinify a stylesheet and compare its source size before and after.
JavaScript MinifierMinify scripts or ES modules while retaining function and variable names.

Which tool do I need?

Start from what you want to do. These are the most common developer jobs and the tool that does each one best.