OpenAnyFile
What is a .hex file?
Intel HEX Firmware is an executable format developed by Intel, first released in 1973. It is usually created by Arduino, STM32, microcontroller toolchains.
ASCII records encoding firmware bytes with addresses and checksums; flashing tools write it into chip memory.
File details
| Full name | Intel HEX Firmware |
|---|---|
| Category | Executables |
| MIME type | text/x-hex |
| Signature (magic bytes) | 3A (:) |
| Developer | Intel |
| Introduced | 1973 |
| Opens with | Text reader |
| Uploaded? | No — read locally in your browser |
How to open a .hex file
OpenAnyFile routes .hex files to its text reader, which shows the full text.
- Drop your .hex 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 text reader.
- 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 full text. 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 .hex 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 .hex files
Can I open a .hex file without installing software?
Yes. OpenAnyFile opens .hex files in your browser using its text reader. You get the full text, with nothing installed and no account.
How do I know a file is really a .hex file?
Check its first bytes instead of its name. A genuine HEX file begins with 3A (:). OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .hex 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.