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webP image's save as .jpg extension

  • 1 reply
  • 1 has this problem
  • 28 views
  • Last reply by cor-el

Tonigau
Tonigau
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When I get item from say Aliex, they have data on a seller page (drawing with detail etc...) https://www.aliexpress.com/item/32989866598.html I download image & it is saved with .Jpg extension (but file is webP format) If I 'inspect element' on image it shows as .jpg, If I 'View image info' it shows as webp (on original web page) Looks like it is webP image file with .jpg extension on their server. ?? (likely to discourage image use) I have IrfranView so no problem viewing/converting etc.. but I need to change extension to reflect the files real format.

Is there a setting in my FF (latest for win7p 64) that I can choose to apply extension of image format to saved file.

Most other image files I save have extension that reflect their format (.jpg, .gif )

thanks

Inspect element: "https://ae01.alicdn.com/kf/HTB1.5pjqrwrBKNjSZPcq6xpapXay.jpg" data-spm-anchor-id="a2g0o.detail.1000023.i0.4ef9766cIBR6FM" width="686" File: location https://ae01.alicdn.com/kf/HTB1.5pjqrwrBKNjSZPcq6xpapXay.jpg

corrected the formatting to remove a leading space which mucks up the readability

When I get item from say Aliex, they have data on a seller page (drawing with detail etc...) https://www.aliexpress.com/item/32989866598.html I download image & it is saved with .Jpg extension (but file is webP format) If I 'inspect element' on image it shows as .jpg, If I 'View image info' it shows as webp (on original web page) Looks like it is webP image file with .jpg extension on their server. ?? (likely to discourage image use) I have IrfranView so no problem viewing/converting etc.. but I need to change extension to reflect the files real format. Is there a setting in my FF (latest for win7p 64) that I can choose to apply extension of image format to saved file. Most other image files I save have extension that reflect their format (.jpg, .gif ) thanks Inspect element: "https://ae01.alicdn.com/kf/HTB1.5pjqrwrBKNjSZPcq6xpapXay.jpg" data-spm-anchor-id="a2g0o.detail.1000023.i0.4ef9766cIBR6FM" width="686" File: location https://ae01.alicdn.com/kf/HTB1.5pjqrwrBKNjSZPcq6xpapXay.jpg ''corrected the formatting to remove a leading space which mucks up the readability''
Attached screenshots

Modified by the-edmeister

All Replies (1)

cor-el
cor-el
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It looks that the alicdn.com server does user agent sniffing and sends a JPG image with Firefox 64 or older and WebP for Firefox 65 and later that support WebP. It doesn't look at the image.http.accept header, so you get a blank image if you disable WebP. It is the same file name, but a different format and file size.

You can verify this with a useragent override via the about:config page in the Network Monitor Firefox 64 - JPEG:

Firefox 65 - WEBP:

Modified by cor-el