WebP very large filesize [5.8 RC2]

According to this article, there is a way to tweak WebP’s quality settings, but it doesn’t seem to help with the problem you’ve discovered.

I noticed the same thing. I uploaded a 1240 x 682 WebP image that is 76.4 KB, created locally by using Imagemagick from a JPEG using a quality setting of 50.

Without touching WP’s WebP settings the filesizes after upload are:

test-150×75.webp 17.7 KB
test-300×150.webp 57.7 KB
test-768×385.webp 293.3 KB
test-800×401.webp 313.3 KB
test.webp 76.4 KB

The smaller-dimension images created by WP are larger in size than the original. Just out of curiosity, I added the following to my functions.php to alter the quality from the default to 50:

// Use a quality setting of 50 for WebP images.
function filter_webp_quality( $quality, $mime_type) {
    if ('image/webp' === $mime_type) {
        return 50;
    }
    return $quality;
}

After that, I re-uploaded the same file and got the same file sizes as before.

I verified that I have ImageMagick/Imagick installed on my server:

### wp-media ###

image_editor: WP_Image_Editor_Imagick
imagick_module_version: 1692
imagemagick_version: ImageMagick 6.9.12-17 Q16 x86_64 2021-06-25 https://imagemagick.org
imagick_version: 3.5.0
file_uploads: File uploads is turned off
post_max_size: 8M
upload_max_filesize: 8M
max_effective_size: 8 MB
max_file_uploads: 20
imagick_limits: 
	imagick::RESOURCETYPE_AREA: 62 GB
	imagick::RESOURCETYPE_DISK: 9.2233720368548E+18
	imagick::RESOURCETYPE_FILE: 768
	imagick::RESOURCETYPE_MAP: 62 GB
	imagick::RESOURCETYPE_MEMORY: 31 GB
	imagick::RESOURCETYPE_THREAD: 1
imagemagick_file_formats: 3FR, 3G2, 3GP, AAI, AI, APNG, ART, ARW, AVI, AVS, BGR, BGRA, BGRO, BIE, BMP, BMP2, BMP3, BRF, CAL, CALS, CANVAS, CAPTION, CIN, CIP, CLIP, CMYK, CMYKA, CR2, CR3, CRW, CUR, CUT, DATA, DCM, DCR, DCX, DDS, DFONT, DNG, DOT, DPX, DXT1, DXT5, EPDF, EPI, EPS, EPS2, EPS3, EPSF, EPSI, EPT, EPT2, EPT3, ERF, EXR, FAX, FILE, FITS, FRACTAL, FTP, FTS, G3, G4, GIF, GIF87, GRADIENT, GRAY, GRAYA, GROUP4, GV, H, HALD, HDR, HISTOGRAM, HRZ, HTM, HTML, HTTP, HTTPS, ICB, ICO, ICON, IIQ, INFO, INLINE, IPL, ISOBRL, ISOBRL6, J2C, J2K, JBG, JBIG, JNG, JNX, JP2, JPC, JPE, JPEG, JPG, JPM, JPS, JPT, JSON, K25, KDC, LABEL, M2V, M4V, MAC, MAGICK, MAP, MASK, MAT, MATTE, MEF, MIFF, MKV, MNG, MONO, MOV, MP4, MPC, MPG, MRW, MSL, MSVG, MTV, MVG, NEF, NRW, NULL, ORF, OTB, OTF, PAL, PALM, PAM, PANGO, PATTERN, PBM, PCD, PCDS, PCL, PCT, PCX, PDB, PDF, PDFA, PEF, PES, PFA, PFB, PFM, PGM, PGX, PICON, PICT, PIX, PJPEG, PLASMA, PNG, PNG00, PNG24, PNG32, PNG48, PNG64, PNG8, PNM, POCKETMOD, PPM, PREVIEW, PS, PS2, PS3, PSB, PSD, PTIF, PWP, RADIAL-GRADIENT, RAF, RAS, RAW, RGB, RGBA, RGBO, RGF, RLA, RLE, RMF, RW2, SCR, SCT, SFW, SGI, SHTML, SIX, SIXEL, SPARSE-COLOR, SR2, SRF, STEGANO, SUN, SVG, SVGZ, TEXT, TGA, THUMBNAIL, TIFF, TIFF64, TILE, TIM, TTC, TTF, TXT, UBRL, UBRL6, UIL, UYVY, VDA, VICAR, VID, VIDEO, VIFF, VIPS, VST, WBMP, WEBM, WEBP, WMF, WMV, WMZ, WPG, X, X3F, XBM, XC, XCF, XPM, XPS, XV, XWD, YCbCr, YCbCrA, YUV
gd_version: 2.3.2
gd_formats: GIF, JPEG, PNG, WebP, BMP, XPM
ghostscript_version: unknown

I’m not sure what the issue is with the large files.

I’m wondering if the large images that are generated are due to our server environments? Surely, the WP developers would have noticed if they were creating smaller-dimension images that are four times the file size of the originals?

I downloaded the WebP images created by my test, and they do show they are of the type “image/webp”.

I SSH’d into an account on my server and ran the Imagick “identify” command to see what I’d find, and it doesn’t show WebP capability:

$ identify -version
Version: ImageMagick 6.9.10-68 Q16 x86_64 2021-02-24 https://imagemagick.org
Copyright: © 1999-2019 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC Modules OpenMP(3.1) 
Delegates (built-in): bzlib cairo fontconfig freetype gslib jng jp2 jpeg lcms ltdl lzma openexr pangocairo png ps rsvg tiff wmf x xml zlib

Next, I set up a test script to output the PHP Imagick formats supported on my test site using the example here.

The table it output does not list WebP under the supported PHP Imagick formats, so that tells me that WP’s report that my server supports WebP via Imagick is probably incorrect.

I uploaded a test JPEG file to the server to try conversion to WebP via the command line with Imagick’s convert command, and I found something interesting that may be part of the problem. When I ran the convert command, I got the following error:

convert: delegate failed 'cwebp' -quiet %Q '%i' -o '%o' @ error/delegate.c/InvokeDelegate/1928.

That makes it look like Imagick’s convert command is using CWebP to do WebP conversions, and CWebP’s command structure is different than Imagick. I wonder if I removed CWebP (libwebp) from the server, if it would fix the issue with the large file sizes WP creates with WebP, and/or no longer list WebP as a compatible format for Imagick?

Do you happen to have libwebp installed on your server?

Can see this too. When uploading a lossy WebP image the scaled down images are much larger than the original. Looks like they are saved as lossless. In my case a 2.5 MB 3000 x 2000 WebP image resulted in a 5.9 MB 2560 x 1707 image.

Opened https://core.trac.wordpress.org/ticket/53653 for this. Please keep an eye on it and test any PRs or patches if possible.

• This reply was modified 3 years, 2 months ago by Andrew Ozz.

Hey @mmxxi – thanks for reporting this.

What tool did you use to create the original WebP image you uploaded to WordPress?

Thanks @mmxxi, @linux4me2, @adamsilverstein. The fix is now committed to trunk. Please test/confirm it if you can. Expecting it’s going to be merged to the 5.8 branch (added to WP 5.8) before RC4 tomorrow.

I also tested with 5.8-RC4, and the compression at default settings is now much better; I got the following with a 76.4 KB, 1280 x 642 pixel, original WebP image:

800×401.webp 51.0 KB
768×385.webp 48.2 KB
300×150.webp 10.9 KB
150×75.webp 4.2 KB

However, if I attempt to change the quality to 50%:

function filter_webp_quality($quality, $mime_type) {
    if ('image/webp' === $mime_type) {
        return 50;
    }
    return $quality;
}
add_filter('wp_editor_set_quality', 'filter_webp_quality', 10, 2);

I’m still getting the same file sizes, so it looks like it’s not possible to set the quality in my child theme’s functions.php with that code snippet.

I switched themes to a child theme of Twenty Twenty, and the snippet worked, so I think that particular problem was at my end.