Category
Developer Tools – Online Utilities & Calculators
Developer-focused formatting, conversion, debugging, and text generation tools that run in the browser with no server-side code processing.
Developer tools here cover the daily small jobs: JSON and XML formatting, regex testing, JWT inspection, timestamp conversion, URL encoding, and code cleanup. All parsing happens in your browser — paste production data without it leaving the machine.
Most used in Developer Tools
JSON Formatter & Validator
Professional developer utility to format, validate, and minify JSON with precise line/column syntax error detection and payload size statistics.
Regex Tester & Debugger
Experiment with regular expressions, inspect every matched occurrence and named capture group, and test replacements with zero server transmission.
JWT Decoder
Read a JSON Web Token header and payload locally. Decoding does not verify the signature.
Color Converter
Inspect and convert colors across all major web and print formats (HEX, RGB, RGBA, HSL, HSLA, HSV, CMYK) in real time with interactive preview.
JSON Diff Checker
Compare two JSON objects or arrays and get a clear, path-addressed report of added, removed, and changed values.
CSV Formatter & Validator
Parse, validate, and reformat CSV with RFC 4180-correct quoting, custom delimiters, column consistency checks, and TSV output.
Image to Base64 Converter
Encode any image into a Base64 data URI entirely in your browser — ready for CSS, HTML, or JSON payloads.
All Developer Tools
HTML Formatter & Minifier
Beautify or minify HTML markup with before/after payload reduction metrics and client-side privacy.
CSS Formatter & Minifier
Format or minify CSS stylesheets in your browser with payload reduction statistics and zero server processing.
Unix Timestamp Converter
Translate epoch timestamps and ISO dates while showing UTC and local browser time.
Lorem Ipsum Generator
Generate predictable placeholder copy for layouts, prototypes, and content testing.
SQL Keyword Line-Breaker
Split dense one-line SQL into one clause per line with uppercase keywords — a readability pass, not a full syntax formatter.
JSON Minifier
Validate and compress JSON into a single line, with exact before/after byte counts and an optional key-sorting step.
XML to JSON Converter
Convert XML to JSON and JSON to XML in your browser, mapping attributes and text nodes with predictable, documented rules.
HTML Entity Encoder & Decoder
Escape text for safe embedding in HTML, and decode named or numeric entities (&, ', ©) back into plain text.
Cron Expression Generator & Explainer
Generate a cron expression from a plain schedule picker, or paste an existing one to get a plain-English explanation and a field-by-field breakdown.
JSON formatting you can trust
The formatter uses the same JSON.parse the language itself uses, so a successful parse means the payload is valid JSON per the spec (RFC 8259). Common failures are trailing commas (invalid), single quotes (invalid — JSON requires double), and unescaped control characters in strings. The error message points to the character position where parsing stopped.
Timestamps and JWTs, demystified
- Unix timestamps are seconds (or milliseconds — the tool detects 10 vs 13 digit values) since 1970-01-01 UTC. Converting shows the result in UTC and your local zone; a "wrong" result is almost always a timezone reading, not a wrong conversion.
- JWT decoding is base64url of the header and payload — it does not verify the signature. A decoded token proves nothing about authenticity; verification requires the secret or public key.
- Regex testing uses the browser’s native engine (JavaScript flavor): lookaheads and named groups work, but lookbehind support depends on browser age.
Common mistakes
- Encoding a whole URL when only query values need encoding (and vice versa) — the path slashes should usually survive.
- Treating a decoded JWT’s exp claim as local time; it is always Unix seconds UTC.
- Pasting JSON with a BOM or trailing newline and assuming the parser is broken.