# MD064 - No Multiple Consecutive Spaces
Aliases: `no-multiple-consecutive-spaces`
## Rule Details
This rule is triggered when multiple consecutive spaces (2 or more) are found
in markdown content. Multiple spaces between words serve no purpose in markdown
and typically indicate formatting issues or copy-paste artifacts.
## Rationale
Multiple consecutive spaces in markdown:
1. **Render as single space**: Most markdown renderers collapse multiple spaces
into a single space, so extra spaces have no visual effect
2. **Indicate potential issues**: Often result from copy-paste errors or
accidental keystrokes
3. **Reduce readability**: Make the source markdown harder to read
## Examples
### Incorrect
```text
This is a sentence with extra spaces.
- List item with extra spaces
> Quote with extra spaces
```
### Correct
```markdown
This is a sentence with single spaces.
- List item with single spaces
> Quote with single spaces
```
## Exceptions
This rule does NOT flag spaces in the following contexts:
### 1. Inline Code Spans
Spaces inside inline code are intentional and preserved:
```markdown
Use `code with spaces` for formatting.
```
### 2. Fenced/Indented Code Blocks
Code block content is not processed:
````text
```
code with intentional spaces
```
````
### 3. Leading Indentation
Leading whitespace for structure is preserved:
```markdown
Indented paragraph (4 spaces)
```
### 4. Trailing Spaces
All trailing spaces are handled by MD009 and are not flagged by this rule:
```markdown
Line with trailing spaces
Another line with trailing spaces
```
Use MD009 to control trailing space behavior.
### 5. Front Matter
YAML/TOML/JSON front matter is not processed:
```markdown
---
title: Document Title
author: John Doe
---
```
### 6. HTML Comments
Content inside HTML comments is not processed:
```markdown
```
### 7. HTML Blocks
Content inside HTML block elements is not processed.
### 8. Table Rows
Table rows with alignment padding are not flagged:
```markdown
| Cell 1 | Cell 2 |
```
GFM-style tables without leading/trailing pipes are also skipped:
```text
Cell 1 | Cell 2 | Cell 3
```
The spaces used for visual alignment in tables are intentional.
### 9. List Marker Spacing
Spaces after list markers are handled by MD030, not MD064:
```text
* Item with extra space after marker
1. Numbered item with extra space
```
### 10. Blockquote Marker Spacing
Spaces after blockquote markers are handled by MD027:
```text
> Quote with extra space after marker
>> Nested blockquote
```
### 11. Reference Link Definitions
Spaces after the colon in reference link definitions:
```text
[ref]: https://example.com
[link]: https://example.com "Title"
```
### 12. Footnote Markers
Spaces after footnote markers:
```text
```
### 13. Definition List Markers
Spaces after definition list markers (PHP Markdown Extra / Pandoc):
```markdown
Term
: Definition text
```
### 14. Task List Checkboxes
Spaces after task list checkboxes:
```markdown
- [ ] Unchecked task
- [x] Checked task
```
Under the `obsidian` flavor, extended checkboxes such as `[/]`, `[-]` and
`[>]` are recognized as well (see the [Obsidian flavor](flavors/obsidian.md)).
### 15. Tab-Width Runs
A run of 4, 8, 12 or any other multiple of 4 spaces is treated as a replaced
tab and is not flagged, so this rule does not undo MD010's tab-to-spaces
conversion at MD010's default width. With `spaces-per-tab` set to 2 or 3, a
tab inside a line becomes a run this rule flags:
```text
Column one column two column three
```
Runs of 2 and 3 spaces, and runs such as 5 or 6 that are not a multiple of 4,
are still flagged. Use MD010 to control tabs and their replacement width.
### 16. Column-Aligned Lists
When a list has at least two items and every item contains a run of two or
more spaces, the spacing is read as deliberate column alignment (the "Useful
commands" section that `cdk init` generates is the classic case) and the item
lines of that list are skipped. A single item has nothing to align with, so it
is checked like any other line. Continuation lines under an item are still
checked. Collapsing the
runs item by item would break the alignment while leaving the document
lint-clean, so the rule keeps the layout instead:
```markdown
- `npm run build` compile typescript to js
- `npm run watch` watch for changes and compile
- `npm run test` perform the jest unit tests
```
Each list is judged on its own items, so a nested list is aligned or not
independently of the list that contains it.
## Fix
The automatic fix collapses multiple consecutive spaces to a single space.
Before:
```text
This is a sentence with extra spaces.
```
After:
```markdown
This is a sentence with extra spaces.
```
When `allow-sentence-double-space` is enabled, the fix preserves exactly 2
spaces after sentence boundaries while collapsing other multiple spaces to 1.
## Configuration
| `allow-sentence-double-space`| boolean | false | Allow exactly 2 spaces after sentence-ending punctuation |
### allow-sentence-double-space
The `allow-sentence-double-space` option enables the traditional typographical
convention of using two spaces after sentence-ending punctuation (`.`, `!`, `?`)
while still flagging multiple spaces elsewhere:
```toml
[MD064]
allow-sentence-double-space = true
```
With this configuration:
```text
End of sentence. Start of next sentence. <- OK (2 spaces after period)
Multiple spaces in middle of sentence. <- Flagged (not after sentence)
What a question! Here's the answer. <- OK (2 spaces after !)
Really? Yes, really. <- OK (2 spaces after ?)
```
#### Recognized Sentence Boundaries
The rule recognizes sentences ending with:
- **Period (.)** followed by spaces (not part of ellipsis or abbreviation)
- **Exclamation mark (!)**
- **Question mark (?)**
Closing punctuation after the sentence-ending punctuation is handled correctly:
```text
"End quote." Next sentence. <- OK (period inside quotes)
She said "Hello!" He replied. <- OK (! inside quotes)
(See appendix.) More content. <- OK (period inside parens)
The book [2024]. Next reference. <- OK (period inside brackets)
```
#### Ellipsis Handling
Ellipsis (`...`) is treated as a sentence boundary, allowing double space after:
```text
And so it goes... The story continues. <- OK (after ellipsis)
```
### Disabling the Rule
To disable this rule entirely:
```toml
[global]
disable = ["MD064"]
```
## Related Rules
- [MD009](md009.md) - Trailing spaces (handles trailing whitespace)
- [MD010](md010.md) - Hard tabs (handles tab characters)
- [MD012](md012.md) - Multiple consecutive blank lines
- [MD027](md027.md) - Multiple spaces after blockquote symbol
- [MD030](md030.md) - Spaces after list markers