OpenAnyFile
What is a .b64 file?
Base64 Encoded File is a data format developed by IETF (RFC 4648). It is usually created by Email tools, APIs, command-line base64.
Binary data written as text. It is decoded here, and the decoded file opens in its own viewer.
File details
| Full name | Base64 Encoded File |
|---|---|
| Category | Data & science |
| MIME type | text/plain |
| Developer | IETF (RFC 4648) |
| Opens with | Base64 decoder |
| Uploaded? | No — read locally in your browser |
How to open a .b64 file
OpenAnyFile routes .b64 files to its Base64 decoder, which shows the decoded file, opened in its own viewer.
- Drop your .b64 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 Base64 decoder.
- 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 decoded file, opened in its own viewer. 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 .b64 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 .b64 files
Can I open a .b64 file without installing software?
Yes. OpenAnyFile opens .b64 files in your browser using its Base64 decoder. You get the decoded file, opened in its own viewer, with nothing installed and no account.
How do I know a file is really a .b64 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 .b64 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.