Plone.scale or addon to convert images to webp

1letter · March 9, 2026, 7:32pm

Is there an add-on to convert uploaded images to WebP? Or does plone.scale support conversion?

thet · March 11, 2026, 1:09pm

There is something in the making: GitHub - bluedynamics/plone-pgthumbor: Thumbor image scaling for Plone — replaces in-ZODB scales with Thumbor URLs. · GitHub

szakitibi · March 13, 2026, 9:46am

There is a script available for converting existing images:

github.com/interaktivgmbh/plone-webp-converter

convert_images_to_webp.py

main

import gc
import logging
import sys
import time
from argparse import ArgumentParser
from io import BytesIO
from typing import Any, Dict, Optional

import transaction
from PIL import Image, ImageSequence, features
from Products.CMFPlone.Portal import PloneSite
from ZODB.POSException import ConflictError
from plone import api
from plone.namedfile.file import NamedBlobImage
from zope.component.hooks import setSite

DEFAULT_OPTIONS = {
    "quality": {
        "default": 85,
        "type": int,

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It is not a ready to be used addon. However it can be used for inspiration to create an IImage added, modified subscriber.

rnunez · March 16, 2026, 5:23pm

WebP should be the default type for all scale from plone. for Pagespeed

mtrebron · March 17, 2026, 2:18pm

That is only valid in your use case. Plone is not only used in web scenarios.

jensens · March 17, 2026, 3:54pm

The nice thing about using Thumbor is, it respects the accept header. So we can deliver whatever the request is asking for.

thet · March 17, 2026, 7:03pm

Recently, at the Classic UI meeting we had a discussion on WebP - @MrTango mentioned that WebP does not well with graphics, especially fonts. AVIF is the superior format.

https://caniuse.com/?search=avif