content-type of text-plain causes browser to download of file

Question

I\'m writing a web application API, where when someone accesses a URL, it returns text data. I set the content-type to \"text/plain\", but when I access it with Chrome, it down

Answer 1

Laurence's explanation is correct. Only IE and Chrome is performing mime sniffing at the time of this post. You can now just set the HTTP header X-Content-Type-Options: nosniff and it will do the trick!

Answer 2

It sounds like you may be running into Chrome Issue 106150. Chrome apparently (sometimes) decides to use "sniffing" logic when the content-type is text/plain.

Possible workarounds:

• Send the X-Content-Type-Options: nosniff header.
• If the text is Unicode, include a BOM. This will tell the sniffing logic that it really is text.
• Remove "binary looking" bytes from the file. From the bug report "Any value between 0x00 and 0x1f looks binary except for ESC, CR, NP, NL, HT".
• It sounds like using an extension that's obviously supposed to be text/plain (like .txt) might disable the sniffing.