# Where is the encoding format stored for a .tex file?

Where is the encoding format stored for a .tex file? I had my editor set to latin1 by mistake when I created my file and I had to resort to

``````% !TEX encoding = UTF-8 Unicode
``````

in the preamble to force UTF-8. I think the file still is encoded in latin1 and this modeline makes the editor ignore the actual encoding and force it to UTF-8.

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The way encoding is treated depends on the editor you use: some assume a particular encoding, some try auto-detection, some respect 'magic comments' such as the one you have. Which editor are you using? –  Joseph Wright Mar 27 '14 at 15:58
TeXstudio 2.7.0 is the editor I use. I noticed I was in trouble when using åäöÅÄÖ and after I opened the file again they had been replaced with Ã and similar. –  user48561 Mar 27 '14 at 16:05
To change a file encoding it's usually easiest to copy-and-paste from the source encoding to the target encoding, and then just overwrite the source with the target. –  Werner Mar 27 '14 at 16:22
Does that give the same result as save as UTF-8 without BOM in notepad++? –  user48561 Mar 27 '14 at 16:34
Accented A are almost always a sign that the file is in UTF-8 but it is being read as latin1, –  David Carlisle Mar 27 '14 at 18:03

You can tell LaTeX what character encoding you are using with for example ``` \usepackage[utf8]{inputenc} ``` or ``` \usepackage[latin1]{inputenc} ```

With Emacs+AUCTeX the editor will recognize that line as well, and change the file's character coding if necessary. With other editors you might not be so lucky. Other than that, it's not really stored in the LaTeX file what encoding it uses, anymore than in other text files.

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Your answer made me realize the difference between exchanging characters and just asking the editor to see it from a new perspective. –  user48561 Mar 27 '14 at 17:00
Sorry, but if you tell your editor the wrong encoding, things can become really strange. –  Keks Dose Mar 27 '14 at 17:10

If you tell LaTeX the encoding of a certain file were latin1, but it is utf-8 in reality, you might encounter strange effects and errors. Even worse: changing encoding while writing...

The encoding of a file is not stored in the file. It might be necessary to reencode your file, here is how to do that: How do I change the encoding of my files?

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My editor always recognized the file as latin1 when re-opening it. That made me think there was encoding information stored somewhere. I think the editor guesses what the content is despite changing \usepackage[latin1]{inputenc} to utf8. –  user48561 Mar 28 '14 at 13:44