images.tooling.report

Returns smallest format possible automatically

Does the default response give you the smallest format possible?

    a child looking into a telescope, pointed upwards

    Introduction

    It is impractical to code a site so all potential image formats are individually hardcoded in them. Tooling should support content negotiation to ship the smallest version of the image possible. This does not mean they always ship AVIF/WebP/Anything else. It means that of the formats supported, the one that is sent to the end user is the smallest available.

    The Test

    An image is requested multiple times, with various Accept headers. The resulting images are compared in filesize, and the smallest of the results should be the one that is sent by default to a user with the most accepting (i.e. most amount of supported formats) Accept header.

    Conclusion

    akamai
    bigCartel
    cloudflare
    cloudinary

    Cloudinary can automaticaly send the best format, but you need to manually set [f_auto](https://cloudinary.com/documentation/image_optimization#automatic_format_selection_f_auto).

    ecwid
    fastly

    By default, original format is requested. You can add an edge worker to improve logic, however.

    goDaddy
    imageEngine
    imaginary
    imgix

    imgix will provide the smallest version, but only when you add ?auto=format to the request

    imgproxy
    optimole
    shopify
    shortPixel
    smush
    squarespace
    thumbor
    webflow

    As webflow does not support AVIF or WebP, this test is not applicable.

    weebly

    As weebly does not support AVIF or WebP, this test is not applicable.

    wix
    Accepts modern image formats as input
    Can it use modern image formats as a source for your optimized image?
    Handles image metadata
    Does it remove cruft, but keep licenses and attributions?