OpenAnyFile
What is a .rmd file?
R Markdown is a text format developed by RStudio (Posit), first released in 2012. It is usually created by RStudio, knitr.
Markdown with executable R chunks; knitting renders it to HTML, PDF or Word.
File details
| Full name | R Markdown |
|---|---|
| Category | Text & markup |
| MIME type | text/markdown |
| Developer | RStudio (Posit) |
| Introduced | 2012 |
| Opens with | Markdown renderer |
| Uploaded? | No — read locally in your browser |
How to open a .rmd file
OpenAnyFile routes .rmd files to its Markdown renderer, which shows the formatted document.
- Drop your .rmd file on the box above, click it to choose the file, or paste it with Ctrl+V.
- The real format is detected from the file's first bytes — not just its name.
- The file opens in the Markdown renderer.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: the formatted document. Size, type, signature and checksums are always shown.
Does not work
Editing and saving back. OpenAnyFile is a viewer, not an editor — for changes you still need the original app.
Is it safe to open a .rmd file online?
Here, yes — because nothing is uploaded. Most "online viewers" send your file to their server. OpenAnyFile reads it with your browser's File API and decodes it on your own device, so there is no copy anywhere else. You can check: open your browser's network tab while opening a file — no upload appears.
Questions about .rmd files
Can I open a .rmd file without installing software?
Yes. OpenAnyFile opens .rmd files in your browser using its Markdown renderer. You get the formatted document, with nothing installed and no account.
How do I know a file is really a .rmd file?
Check its first bytes instead of its name. This format has no fixed signature, so the detected type and the readable content are the best clues. OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .rmd file uploaded anywhere?
No. The file is read locally by your browser and never sent to a server — it even works offline once the page has loaded.
Does it work on phones?
Yes — on Android and iPhone, in any modern browser. You can also install OpenAnyFile as an app.
Related formats
Other formats from the same family:
Format facts checked and page updated on September 25, 2026.