Stop Pushing Broken Markdown: Use a Preview Tool First

You write a README, push to GitHub, and the formatting is wrong. Headings are not headings. The code block is missing its language tag. The table is a mess. You edit, push again, wait for it to render, and hope it is fixed this time.

This is why a Markdown preview tool saves so much time. Write on the left, see the rendered output on the right, and catch mistakes instantly.

Common Markdown mistakes that preview catches

Headings need a space after the #. ##Heading will not render as a heading, but ## Heading will. This is the most common mistake and the preview shows it immediately.

Tables are the worst. The separator row needs exactly the right number of pipes and dashes. One missing pipe and the whole table breaks. The preview shows your table as it will actually render.

Code blocks need a blank line before them in some Markdown flavors. If your code is squished into the previous paragraph, the preview catches it. Language tags on code blocks — ```python vs ``` — control syntax highlighting. The preview shows you exactly how the highlighting will look.

Nested lists need exactly the right indentation. Two spaces or four? The spec says two, but some parsers require four. The preview removes the guesswork.

Quick syntax reference

# H1 Heading
## H2 Heading
### H3 Heading

**bold text**
*italic text*
~~strikethrough~~
`inline code`

[link text](https://example.com)
![alt text](image.jpg)

- Unordered list item
- Another item

1. Ordered list item
2. Another item

| Column 1 | Column 2 |
|----------|----------|
| Cell 1   | Cell 2   |

```python
print("code block with syntax highlighting")
```

When to use each Markdown flavor

GitHub Flavored Markdown (GFM) is the most common. It supports tables, task lists (- [ ] and - [x]), strikethrough, and auto-linked URLs. Use this for README files, issues, PR descriptions, and documentation hosted on GitHub or GitLab.

CommonMark is the strict standard. No tables, no task lists, no strikethrough. Use this when you need guaranteed compatibility across all Markdown parsers — or when writing for a platform that explicitly uses CommonMark.

The Markdown preview tool supports GFM. Write, preview, copy the formatted output or the raw Markdown. It is the fastest way to check your formatting before pushing.