What is an EOT file?

What EOT is

EOT is a binary format, meaningful only to a program that knows it. It is used for the web.

The extension is .eot, and the full name is Embedded OpenType. Both matter less than what the file can hold, which is what the rest of this page is about.

Where EOT came from

Microsoft published it in 1997.

A format that has been readable for that long is a format worth trusting with something you want back in ten years.

The specification belongs to its vendor

Reading it outside the vendor’s own software depends on work done by other people, usually by inspection rather than by documentation. That mostly works and occasionally does not, which is the reason to convert anything you intend to keep.

It has been superseded

The people who made it have moved on, and support is being withdrawn rather than added. Anything still in this format is worth moving while the tools to move it are still around.

What opens EOT

fonttools reads it, and so do most programs of the same kind.

If a file will not open, the format is rarely the problem — it is more often that the program predates it. Converting to something older is the reliable way past that, and it is what the rest of this site is for.

Opening it in a browser

No browser reads it.

That is the single most common reason to convert it: not that the format is bad, but that the place you want to show the file cannot read it.

It is a delivery format

EOT is meant to be handed over rather than worked in. Editing one is possible and rarely pleasant; the sane approach is to change the source and export again.

What goes wrong with it

The recurring complaints: support outside its home ground is uneven.

None of these is a reason to avoid the format. They are the things worth knowing before you are surprised by one, which is a different claim and a more useful one.

The facts, in one place

Formats worth considering instead of EOT

• Web Open Font Format 2
• TrueType Font