Edit code / data online
The best free online tools to edit code / data, ranked and filterable.
20 tools to edit code / data
CodePen
HTML, CSS, JS
HackMD
Markdown
HTML5 Editor
HTML
JSFiddle
HTML, CSS, JS
Milkdown
Markdown
Online HTML Editor
HTML
StackBlitz
All Web Formats
StackEdit
Markdown
The Hydra
Comprehensive developer toolkit
WordCounter.net
Text (Count)
Editor.md
Markdown
EditPad Alphabetizer
HTML/Text; Text; Text to Image
FreeTextTools Reverse Text
Text (Reverse)
Glitch
All Web Formats
Ideone
60+ Languages
JDoodle
70+ Languages
OnlineGDB
C, C++, Java, Python
Paraphraser.io
Image to Text; Text; Text to Image
PrePostSEO Add Line Breaks
Binary to Text; C#; CSS; HTML; Image to Text; JS; JSON; PDF to Word; PHP; Python; Ruby; SQL; Text; Text to Binary; Text to Image; Web; XML
Replit
All Programming Formats
Side-by-side comparison
| Tool | Free | No signup | No watermark | Quality | Speed |
|---|---|---|---|---|---|
| CodePen | Yes | Yes | Yes | high | medium |
| HackMD | Yes | Yes | Yes | high | medium |
| HTML5 Editor | Yes | Yes | Yes | high | medium |
| JSFiddle | Yes | Yes | Yes | high | medium |
| Milkdown | Yes | Yes | Yes | high | medium |
| Online HTML Editor | Yes | Yes | Yes | high | medium |
| StackBlitz | Yes | Yes | Yes | high | medium |
| StackEdit | Yes | Yes | Yes | high | medium |
Frequently asked questions
What's the best free tool to edit code / data?
We rank tools by "Best match" — free, no signup, no watermark, and quality. The top card above is usually the safest starting point to edit code / data.
Can I edit code / data without signing up?
Yes. Toggle "No signup" above and you'll only see tools that let you edit code / data straight from your browser, no account required.
Are these edit tools really free?
Most are fully free; some are freemium with paid limits. Use the "Pricing" filter to see only free tools, and check the limits on each card.
Will quality drop when I edit code / data?
Quality depends on the tool. Filter by "Quality: High" to only see tools we've graded as preserving fidelity when you edit code / data.