JSON, CSS, encoding and number-system tools for everyday development work — formatting, converting, comparing and validating, with the working shown.
Browse Web & Developer
- JSON ToolsFormat, inspect, transform and compare JSON — processed privately in your browser.24 tools
- JSON Schema ToolsGenerate, validate and explore JSON Schema (draft 2020-12) — processed privately in your browser.4 tools
- Data ConvertersConvert JSON to TypeScript, Markdown, and other developer formats — processed privately in your browser.15 tools
- CSS ToolsVisual CSS generators with live previews — shapes, effects and layout code you can copy straight into your stylesheet.14 tools
- Tailwind CSS ToolsGenerators, converters and cleanup tools for Tailwind CSS — v3 and v4 aware, with live previews.22 tools
- Encoding and Decoding ToolsEncode and decode Base64, URLs, HTML entities, Unicode, JWTs and classical ciphers.50 tools
- Number System ConvertersConvert numbers between binary, octal, decimal, hexadecimal and any base up to 62 – with exact BigInt arithmetic, visible calculation steps and fraction support.52 tools
- Signed Number ToolsTwo’s complement, one’s complement, sign-magnitude, bit widths, fixed-point and IEEE 754 – how machines really store signed and fractional numbers.9 tools
- Digital Electronics ToolsGray code, BCD and Excess-3 converters with full tables – the classic codes of digital circuits, encoders and decimal hardware.7 tools
Good places to start
- JSON FormatterPretty-print JSON with your choice of 2-space, 4-space or tab indentation, with optional alphabetical key sorting.
- JSON ValidatorCheck whether text is valid JSON per RFC 8259.
- Base64 EncoderConvert text or Unicode characters into Base64 – the binary-to-text encoding used by email attachments, data URIs and HTTP basic authentication.
- URL DecoderDecode percent-encoded URLs back to readable text, with an optional plus-as-space rule and a repeat mode that unwraps double-encoded values such as %253A.
- Binary to Decimal ConverterConvert a binary number to decimal by summing the place values – each 1 bit contributes its power of two.
Frequently asked questions
Is the JSON or code I paste sent to a server?
No. Every tool in this category runs in your browser, so a payload with customer records or credentials in it never leaves your machine. That is the reason these are usable at work, where pasting production data into an unknown web service usually is not.
What is the difference between formatting and minifying JSON?
Formatting adds indentation and line breaks so a human can read the structure. Minifying strips every byte of whitespace so a machine can transfer it faster. The data is identical either way; they are the two ends of the same job, one for you and one for the wire.
What does the JSON validator tell me that my editor does not?
The exact line and column where parsing failed, and what was expected there. Browsers report a character offset with no context, which is close to useless in a 4,000-line file, so these tools carry their own scanner to produce a message you can act on.
Do the encoders and converters handle Unicode correctly?
Yes. Text is encoded as UTF-8 before Base64 or percent-encoding is applied, so accented characters, non-Latin scripts and emoji survive a round trip intact. Emoji are a good test case because they are outside the Basic Multilingual Plane and break naive implementations.
Which number bases can be converted?
Any base from 2 to 36, with dedicated tools for binary, octal, decimal and hexadecimal. The signed-number tools additionally cover two's complement, one's complement and sign-magnitude at 8, 16, 32 and 64 bits, where the bit width changes the answer.
Are the CSS and Tailwind outputs valid for current versions?
The colour work follows the CSS Color 4 specification, and the Tailwind palettes are extracted from the official Tailwind packages rather than typed by hand. Tailwind v3 and v4 palettes genuinely differ, because v4 rebuilt them in OKLCH, so the tools keep both.
Can I chain these tools together?
Yes, and that is how most of them are meant to be used. Validate JSON, then format it, then minify what you ship. Or convert a colour, build a scale from it, then check the contrast. Each tool links to the ones that usually come next.
