README

What is a .readme file?

The first thing anyone reads when they land on a repo — what the project does, how to install it, and how to use it.

Safe format
Type Document
By N/A (developer convention)
MIME text/plain

Drop any file to identify it

No upload. No signup. No sending your file halfway across the internet.
We tell you what it is, right here in your browser.

What is it

The README is a project's front door. Open any repo on GitHub, GitLab, or Bitbucket and the README is automatically displayed beneath the file listing. A good one tells a visitor in 30 seconds: what this project does, who it's for, how to install it, how to use it, and where to go for more help. Without a good README, even excellent code goes unused — nobody installs what they can't figure out.

Most READMEs are written in Markdown (README.md) because every code-hosting platform renders Markdown automatically — headings become big, code blocks get syntax highlighting, links work. Plain-text READMEs (just `README` with no extension, common in older Unix projects) still work but render as a wall of monospace. The conventional structure: project title and one-line description, badges (build status, version, license), short example, installation instructions, usage examples, link to full docs, contributing guidelines, license.

GitHub elevates the README beyond a single file. Putting a README.md in a repo named after your username (github.com/yourname/yourname) creates a profile README that displays on your GitHub profile. Putting one in `.github/profile/` for an organisation does the same thing. Within a project, GitHub looks for README files at the root and inside any directory, so you can have a top-level README plus per-folder READMEs documenting subdirectories. The casing and extension are flexible — `README`, `README.md`, `Readme.md`, `readme.txt` all work — but uppercase README.md is the strongest convention.

Technical details
Full Name
README
MIME Type
text/plain
Developer
N/A (developer convention)
Magic Bytes
N/A
Safety
.readme is a known, safe format.
What opens it
Any text editor
FREE All
GitHub (web)
FREE All

* Renders Markdown automatically

FAQ
What's the difference between README and README.md?
README is plain text; README.md is Markdown. GitHub and other code-hosting platforms render Markdown with formatting (headings, code blocks, links, images), so README.md is almost always the better choice. The plain README convention dates back to the 1980s when READMEs were just plain text shipped with software.
Why is README always uppercase?
Tradition, originally combined with the practical effect that uppercase filenames sort to the top of `ls` output on Unix systems — making the README more discoverable when you list a directory. Modern file managers don't preserve this sort order, but the convention stuck.
Related formats