Tool collections

For Developers

Practical file tools for documentation, data, and verification.

View all tools
Selected tools

Start with the right tool

12
Browser tools

Fast tools in your browser

20
Browser-local

JWT Decoder

Decode a JWT header and payload locally only; signature is unverified.

Open tool
Browser-local

Query String Parser/Builder

Parse a query string or build one from key=value lines.

Open tool
Browser-local

HTML Entity Encode/Decode

Encode or decode HTML entities in your browser.

Open tool
Browser-local

Unicode Inspector/Escape Converter

Inspect Unicode code points or convert text to escapes.

Open tool
Browser-local

Cron Expression Explainer

Explain a standard five-field cron expression.

Open tool
Browser-local

Color Contrast Checker

Check foreground and background contrast against WCAG.

Open tool
Browser-local

Semantic Version Comparator

Compare two semantic versions.

Open tool
Browser-local

Text Secret Redactor

Hide visible emails, tokens, and keys locally before sharing text.

Open tool
Browser-local

URL Parser

Parse URL components locally.

Open tool
Browser-local

Regular Expression Tester

Test a JavaScript regular expression against text locally.

Open tool
Browser-local

HTTP Status Lookup

Show a short description for a common HTTP status code.

Open tool
Browser-local

CSS Unit Converter

Convert between px and rem using a root font size.

Open tool
Browser-local

Text Difference Checker

Show added and removed lines between two texts.

Open tool
Browser-local

Slug Generator

Create a simple slug from a title.

Open tool
Browser-local

MIME Type Lookup

Look up a common MIME type for a file extension.

Open tool
Browser-local

IPv4 Address Converter

Convert an IPv4 address to decimal and back locally.

Open tool
Browser-local

Line Ending Converter

Convert text line endings to LF or CRLF.

Open tool
Browser-local

HTML Tag Stripper

Extract text from HTML locally.

Open tool
Browser-local

Text Case Converter

Convert text to camelCase, snake_case, or kebab-case.

Open tool
Browser-local

Duplicate Line Remover

Remove duplicate lines while preserving order.

Open tool
Developer tools

Tools that run locally in your browser