77 tools · runs in your browser
Your Developer Toolkit.
All in One Place.
Format JSON, decode a JWT, hash a string, convert a timestamp, draw a diagram. 77 tools that load instantly and never send your input anywhere.
json-formatterVALID
// input
{"name":"devkithub","tools":77,"local":true}// output
{
"name": "devkithub",
"tools": 77,
"local": true
}Start here
A cross-section of the catalogue — one from each area.
- JSON FormatterFormat and beautify JSON with configurable indentation and optional key sorting. Runs entirely in your browser.Open tool
- JWT DecoderDecode a JWT header and payload, see exactly when it expires, and get warned about alg none and millisecond timestamps. Runs in your browser.Open tool
- Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text at once, bit-exact against the published specification vectors, in your browser.Open tool
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date and back. Detects seconds, milliseconds, microseconds and nanoseconds, and always answers in UTC.Open tool
- CSV to JSON ConverterConvert CSV to JSON with a real RFC 4180 parser that handles quoted commas, embedded newlines and escaped quotes, and keeps 007 and long ids as text.Open tool
- Color ConverterConvert between HEX, RGB, HSL and HSV, and check WCAG contrast. Uses the published luminance formula, not a brightness average.Open tool
Browse by category
- JSON & DataFormat, validate, compare and convert structured data.18 tools
- Encoding & ConversionEncode, decode and convert between common text formats.10 tools
- API & SecurityInspect tokens, build requests and generate identifiers.18 tools
- ProgrammingEditors, playgrounds and generators for everyday coding.31 tools
Visual Lab
Diagrams that live in a URL
Draw a flowchart or write a sequence diagram, then copy an image URL that renders it anywhere Markdown works. The whole document is encoded in the link, so there is nothing to upload and nothing that can be deleted out from under your README.
README.md
## Login flow
Why DevKitHub
- Private by default
- Every tool here processes your input in the browser. Nothing is uploaded, stored or logged — and each page states exactly where processing happens.
- Errors that help
- Invalid input gets the exact line and column it failed on, not a generic "something went wrong".
- Keyboard accessible
- Full keyboard navigation, visible focus rings, screen-reader announcements and reduced-motion support throughout.