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JSON & data

Encode & convert

Text & writing

Web & design

URLs

URL Builder URL Cleaner UTM Builder Text Fragment Link

Outlook Safelink Decoder SharePoint URL Decoder

HTTP & headers

HTTP Status Codes

MIME Types Cache-Control Builder Cookie Parser HAR Sanitizer

User-Agent Parser

Basic Auth Generator

API Tester WebSocket Tester

Security

CSP Generator Security Headers Generator security.txt Generator

HTML

HTML WYSIWYG Editor HTML Prettifier HTML to Markdown HTML Table to CSV / JSON HTML to XHTML HTML Cleaner

CSS Selector ↔ XPath

SEO

OG Meta Generator robots.txt Generator Web App Manifest Generator Social Share Links

Email

Mailto Link Generator

Email Normalizer Email Parser (.eml)Email Bounce Parser

DMARC Report Analyzer

Browser & device

Keyboard Tester

Keycode Info Screen Test Stopwatch & Timer

Markdown

Markdown to HTML

Markdown to Plain Text

Markdown TOC Generator

Markdown Table Generator Markdown Table Formatter Markdown Editor Markdown Format Converter Paste as Markdown Markdown Table to Data

Markdown Lorem Ipsum

EPUB to Markdown

Dev & ops

Security

Generate & media

Calculators & reference

English

Changelog Attributions

© 2026 Daniel Chen

PrismKit

Web

Screen Test

Screen Test

Runs in your browserLocal

Hunt for dead or stuck pixels with fullscreen solid colours, a gradient and a checkerboard, and see your screen's resolution, pixel ratio and refresh rate.

Keycode Info

Press any key to see its JavaScript key, code, keyCode, location, and active modifiers.

Stopwatch & Timer

A stopwatch with laps, a countdown timer that beeps when done, and a configurable Pomodoro timer that stays accurate in background tabs.