CommonMark & GFM Markdown Beautifier, Minifier & HTML Preview
Markdown Formatter
Beautify, format, validate, and preview Markdown documentation with heading level hierarchy, GFM tables, code block protection, reading time estimates, and safe HTML preview.
Load Preset Template:
Line Wrap (Print Width):
Prose Wrapping:
Input Markdown Code
0 chars0 chars
Markdown Structure Valid: No syntax errors detected.
CommonMark / GFM ValidLines:0|Words:0 words|Reading Time:0 min|Byte Size:0 B|Headings (#):0|Code Blocks:0|Lists:0|Tables:0|Links:0
CommonMark & GFM Markdown Standards & Developer Specification Reference
Heading Hierarchy & ATX Rules
Preserves ATX heading levels (# H1 through ###### H6) and Setext headings without changing heading levels or deleting titles.
XSS Sanitization & Safe Preview
Live HTML preview is rendered inside a sandboxed <iframe sandbox="allow-forms">, sanitizing scripts (<script>) and javascript: links.
GFM Tables & Task Lists
Full support for GitHub Flavored Markdown (GFM) pipe tables with alignment specifiers (:---, :---:) and task list checkboxes (- [x]).
Verbatim Code Block Protection
Code contents inside fenced code blocks (```) are preserved verbatim without running Markdown formatting inside programming scripts.