{"id":7806,"date":"2025-09-10T17:35:24","date_gmt":"2025-09-10T14:35:24","guid":{"rendered":"https:\/\/mummila.net\/kommentit\/?p=7806"},"modified":"2025-09-10T17:35:24","modified_gmt":"2025-09-10T14:35:24","slug":"download-link-for-files-converted-from-avif-to-png-or-webp-produces-jpegs-in-firefox","status":"publish","type":"post","link":"https:\/\/mummila.net\/kommentit\/2025\/09\/10\/download-link-for-files-converted-from-avif-to-png-or-webp-produces-jpegs-in-firefox\/","title":{"rendered":"Download link for files converted from AVIF to PNG or WebP produces JPEGs in Firefox"},"content":{"rendered":"

Describe the bug<\/strong>
\nI’m getting inconsistent results when converting AVIF images to other formats, using Firefox (in Ubuntu). I’m self-hosting Mazanoke 1.1.5, but the results are the same with mazanoke.com.<\/p>\n

To Reproduce<\/strong>
\nSteps to reproduce the behavior:<\/p>\n

    \n
  1. Download\u00a0this example AVIF file<\/a>\u00a0(as raw)<\/li>\n
  2. In Mazanoke, select Convert to: PNG<\/li>\n
  3. Drag and drop the AVIF file into the browser<\/li>\n
  4. Click the Download button of the converted file<\/li>\n<\/ol>\n

    Expected behavior<\/strong>
    \nto receive a PNG file,\u00a0fox.profile0.10bpc.yuv420.png<\/code><\/p>\n

    Screenshots<\/strong>
    \nI receive a JPEG file, named\u00a0fox.profile0.10bpc.yuv420.jpeg<\/code><\/p>\n

    Desktop (please complete the following information):<\/strong><\/p>\n

      \n
    • OS: Ubuntu 24.04<\/li>\n
    • Browser Firefox 142.0.1<\/li>\n<\/ul>\n

      Additional context<\/strong>
      \nThe same thing (i.e. receiving a JPEG file) happens if I choose WebP as output, but not if I choose ICO: downloading the latter does produce a\u00a0fox.profile0.10bpc.yuv420.ico<\/code>, as expected.<\/p>\n

      Choosing JPG output also works as expected (although it would be pretty funny if it didn’t). Notably, this produces the filename\u00a0fox.profile0.10bpc.yuv420.jpg<\/code>: the file extension differs from the one produced by Firefox for the unexpected cases (.jpeg<\/code>).<\/p>\n

      I can also work around the issue by selecting ”Download all”, which produces a zip archive, and all the files therein are in my chosen output formats as listed.<\/p>\n

      In Vivaldi (which is based on Chrome) the Download link also does produce the file in the chosen output format. So this looks like Firefox-specific issue.<\/p>\n

      Converting from (and to) other formats seems to work as expected in Firefox (at least the ones I’ve tested so far).<\/p>\n","protected":false},"excerpt":{"rendered":"

      I’m getting inconsistent results when converting AVIF images to other formats, using Firefox. Instead of PNG of WebP files, I receive JPEGs.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8860],"tags":[11987,546,23022,2679,23023],"class_list":["post-7806","post","type-post","status-publish","format-standard","hentry","category-vianhallintajarjestelmat","tag-chrome","tag-firefox","tag-mazanoke","tag-ubuntu","tag-vivaldi","sijainti-github"],"_links":{"self":[{"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/posts\/7806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/comments?post=7806"}],"version-history":[{"count":1,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/posts\/7806\/revisions"}],"predecessor-version":[{"id":7807,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/posts\/7806\/revisions\/7807"}],"wp:attachment":[{"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/media?parent=7806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/categories?post=7806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mummila.net\/kommentit\/wp-json\/wp\/v2\/tags?post=7806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}