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Imgwire Supported Image Types

Imgwire accepts common web image formats and several source formats that are useful for imports, migrations, and generated media workflows. This guide explains which formats you can upload and how to choose delivery formats for browsers.

Supported upload MIME types​

Imgwire currently accepts these image MIME types for uploads:

MIME typeTypical extension
image/jpeg.jpg, .jpeg
image/jxl.jxl
image/png.png
image/webp.webp
image/avif.avif
image/gif.gif
image/vnd.microsoft.icon.ico
image/heic.heic
image/bmp.bmp
image/tiff.tif, .tiff

Client API keys can also restrict uploads to a subset of these types with allowed_mime_types. Use that setting when your frontend should only accept specific formats, such as JPEG and PNG uploads for avatars.

Direct delivery and transformed delivery​

Some uploaded formats are directly browser-friendly. Imgwire marks JPEG, PNG, WebP, AVIF, and GIF images as directly deliverable.

Other accepted upload formats, such as JXL, ICO, HEIC, BMP, and TIFF, are useful as source images but are not ideal public web responses. For those inputs, request a browser-friendly transformed variant for delivery:

https://cdn.imgwire.dev/{organization_id}/{environment_id}/{image_id}?format=auto&quality=auto

Use the Format transformation when you need a specific output format:

Output valueUse when
autoImgwire should choose a browser-friendly response format
jpg/jpegYou need broad compatibility and do not need transparency
pngYou need PNG output, often for transparency or lossless content
webpYou want explicit WebP output
avifYou want explicit AVIF output
gifYou need GIF output
tiffYou need TIFF output for a downstream workflow

Choose formats by use case​

For public web and app delivery, start with format=auto&quality=auto. Imgwire can use the request's browser capabilities to choose an appropriate output while keeping your application code format-agnostic.

Use explicit formats when you have a real requirement:

  • Use png when preserving transparency in PNG output matters.
  • Use jpeg when a downstream tool only accepts JPEG.
  • Use webp or avif when you are creating a known modern-browser variant.
  • Use gif when you intentionally want GIF output.
  • Use tiff for workflows that require TIFF output rather than browser delivery.

Animated images​

Animated inputs need a delivery format that supports animation if you want the delivered variant to remain animated. GIF, WebP, and AVIF can preserve animation. JPEG, PNG, and TIFF outputs are still-image formats, so use them only when a still result is acceptable.

Best practices​

  • Restrict allowed_mime_types on Client Keys to the formats your UI actually supports.
  • Use format=auto for browser-facing images unless you need a specific format.
  • Pair format selection with quality=auto for public image delivery.
  • Store the original image ID so you can generate new variants later without re-uploading.
  • Test representative content, such as screenshots, product photos, portraits, and generated images, before choosing explicit format rules.

Common mistakes​

  • Assuming every accepted upload format should be served directly to browsers.
  • Accepting all image types in the UI when your app only handles a smaller set.
  • Forcing one output format globally without checking transparency, animation, and browser requirements.
  • Treating format transformations as changes to the original uploaded file. They only affect delivered variants.

Last updated at: May 8, 2026