Free gitignore test files and sample generator
Glob patterns Git uses to exclude files. Generate valid .gitignore sample files for testing tooling and repo scaffolding.
What is a .gitignore file?
.gitignore: Git Ignore Patterns. A .gitignore file lists glob patterns Git uses to exclude paths. Pattern precedence and negation are subtle, so tooling that reimplements the rules benefits from realistic samples.
Why generate a test gitignore file?
- Test an ignore-pattern implementation in your own tooling.
- Check repository-scaffolding templates.
- Exercise performance with a long pattern list.
How a .gitignore file is identified
A .gitignore file has no signature at the start. A text format has no identifying leading bytes, so the extension and the reported media type are the only claims about it until a parser actually reads it, which is why validating uploads by extension alone is unsafe.
How the size lands on the exact byte
The format allows comments, so the padding is comment lines, legal, inert, and visible if you open the file.
Negative testing with broken gitignore files
- Invalid. Identifiable, but wrong inside, so it fails during parsing.
- Corrupted. The leading bytes are destroyed. Same length as the valid file.
- Incomplete. Truncated part-way, so it is genuinely shorter.
- Empty. Chosen under Content rather than File Condition: valid structure, no data.
Which failure to reach for, and what to assert for each, is covered in how to make a corrupted file for testing. For upload limits and type checks see testing file upload validation, and for this format's encodings, UTF-16 and BOM test files.
Sample gitignore content
# .gitignore build_0/*.tmp build_1/*.tmp
This shows the shape of the file. Your download is generated fresh at the size you choose, so the values will differ.
How to open and verify the file
Check behavior with `git check-ignore -v <path>`.
Media type text/plain · extension .gitignore · category Config & DevOps
Generate a .gitignore file → · questions about sizes, privacy or cost are answered on the site FAQ.
Frequently asked questions about gitignore files
What identifies a .gitignore file?
Nothing at the start of the file does. A text format has no identifying leading bytes, so the extension and the reported media type are the only claims about it until a parser actually reads it, which is why validating uploads by extension alone is unsafe.
How can a .gitignore file be an exact number of bytes?
The format allows comments, so the padding is comment lines, legal, inert, and visible if you open the file.
Can I download several broken gitignore files at once?
Yes, select more than one File Condition and you get one ZIP containing a .gitignore per condition, each named after its condition.
Can the gitignore file use UTF-16 or a byte-order mark?
Yes. .gitignore is a text format, so it can be generated as UTF-8, UTF-8 with a byte-order mark, UTF-16 LE or UTF-16 BE. The body is shortened before re-encoding so the finished file still lands on the exact size you asked for. Note that a UTF-16 file always has an even byte count.
How do I open or verify the gitignore file?
Check behavior with git check-ignore -v <path>.
Related Config & DevOps formats
ENV · INI · TOML · Dockerfile · CONF · Properties · Makefile · EditorConfig