Bytes Converter
Convert between bytes, KiB, MB, GB and bits, in both systems.
Developer Tools
Format, encode and hash without leaving the tab.
167 free tools
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Port Number Lookup
Find what runs on a port, with a note on whether it should be exposed.
Fake Company Generator
Generate believable company names, domains and details for mockups.
UUID Generator
Generate cryptographically random version 4 UUIDs in bulk.
Unicode Code Point Lookup
Inspect any character: code point, block, category, UTF-8 bytes and escapes.
CSS Formatter
Re-indent a stylesheet, or strip it back to one line.
CSS Triangle Generator
Generate the border trick that makes triangles and tooltip arrows.
TOML Formatter
Tidy a TOML file: consistent quoting, ordered tables, keys before headers.
JSON Formatter
Beautify, minify and validate JSON with precise error locations.
IBAN Validator
Validate an IBAN's length, country and mod-97 checksum, and generate test ones.
CSV to SQL
Turn a CSV export into INSERT statements, with column types inferred.
XPath Tester
Run XPath expressions against your own XML and see every node that matches.
Duration Converter
Convert a duration between seconds, ISO 8601, clock time and words.
README Generator
Fill in the fields and get a complete README.md in Markdown.
Regex Tester
Test a regular expression live, with every match and capture group shown.
ULID Generator
Generate ULIDs — sortable by creation time and case-insensitive.
JSONPath Tester
Run JSONPath expressions against a document and see every match live.
YAML Validator
Check YAML parses and find the line where the indentation goes wrong.
Mock JSON Generator
Describe a shape and get as many rows of matching JSON as you need.
CRC32 Calculator
Compute a CRC-32 checksum in hex, decimal and signed form.
XML Minifier
Strip whitespace and optionally comments from XML, and see the bytes saved.
package.json Generator
Build a valid package.json with scripts, exports and metadata.
CIDR Range Calculator
Work out a subnet: network, broadcast, host range and usable count.
SVG to JSX
Turn an SVG into a React component with the attributes React expects.
Dockerfile Generator
Generate a production Dockerfile with multi-stage builds and layer caching.
IP to Binary Converter
See an IP address in binary, hex and decimal, octet by octet.
AES Encrypt & Decrypt
Encrypt text with a password using AES-GCM, and decrypt it back.
Gitignore Generator
Build a .gitignore from templates for your stack, editor and OS.
HTML to Markdown
Convert HTML back into clean Markdown, keeping lists, tables and code.
JSON Validator
Check JSON syntax and get the exact line, column and cause of any error.
Hash Generator
Produce SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text.
Slugify for Developers
Turn any text into a safe slug, filename, anchor or branch name.
UUID v5 Generator
Generate deterministic UUIDs from a namespace and a name.
JWT Decoder
Decode a JWT and read its header, claims and expiry in plain English.
JSON to SQL Insert
Turn an array of JSON records into INSERT statements, with an optional CREATE TABLE.
License Generator
Pick an open source licence and get a LICENSE file with your details.
JSON to TypeScript
Generate TypeScript interfaces from a sample JSON payload.
JSON Minifier
Strip every optional byte from a JSON document and see what you saved.
Browser Info Checker
Your browser, engine, platform, languages and what it supports.
Variable Name Converter
Convert a name between camelCase, snake_case, kebab-case and the rest.
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About these developer tools
A developer utility belt that works offline. Pretty-print and validate JSON, encode or decode Base64 and URLs, generate UUIDs and produce SHA hashes. No installs, no sign-up, and your payloads never leave your machine.