SweetLemon Lab
A growing library of free tools that run in your browser. No signups, no tracking, no ads. Built because we needed them.
Unit Converter
Unit Converter
Convert between units of length, weight, area, volume, temperature, and speed — instant, offline, no signup.
Open app →Time
Time
Convert timestamps, durations, timezones, date diffs, and calendars — all in one place.
Open app →Markdown Editor
Markdown Editor
Write and preview Markdown with a live three-pane editor — no signup, no server, runs entirely in the browser.
Open app →Emoji, Unicode & ASCII
Emoji, Unicode & ASCII
Find any emoji, look up Unicode characters, and reference the ASCII table — instant copy to clipboard.
Open app →ASCII Art
ASCII Art
Turn text into ASCII banners, wrap in Unicode boxes, or convert images to character art.
Open app →Typing Trainer
Typing Trainer
Practice typing with prose, code, numbers, and scripts — track WPM, accuracy, and problem keys.
Open app →JSON Formatter
JSON Formatter
Format, validate, minify, and explore JSON. Pinpoint parse errors with line and column.
Open app →UUID, Hash, Base64, JWT & URL
UUID, Hash, Base64, JWT & URL
Generate UUIDs, compute hashes, encode Base64, decode JWTs, and encode URLs — all in one tab.
Open app →Text Diff
Text Diff
Compare two texts and see additions, removals, and changes with word or line precision.
Open app →Cheatsheets & Drill
Cheatsheets & Drill
CLI, editor, and tool cheatsheets with practice drills. Build muscle memory.
Open app →