When uploading images in AVIF format, they are displayed as JPG.

[bagow]

Bug Description

When uploading images in AVIF format, they are displayed as JPG.

Steps to reproduce

1. Go to media
2. Click on upload media
3. Select any avif file on your computer
4. See on site front jpg

[westonruter]

Can you share your Site Health information? This has key information about what image libraries are available in your site.

[hbhalodia]

Hi @westonruter @bagow, If I am correct, I tried to follow the steps mentioned in the issue description and uploaded a avif file and added it on page using image block and on frontend, it shows avif and jpg in srcset, but src being used is avif.

See the below screencast for the reference,

ImageAVIFJPGIssue.mov

Also, below is the site health information,

Site Health Information

### wp-core ###

version: 6.7.1
site_language: en_US
user_language: en_US
timezone: +00:00
permalink: undefined
https_status: false
multisite: false
user_registration: 0
blog_public: 0
default_comment_status: open
environment_type: local
user_count: 1
dotorg_communication: true

### wp-paths-sizes ###

wordpress_path: /var/www/html
wordpress_size: 266.44 MB (279386477 bytes)
uploads_path: /var/www/html/wp-content/uploads
uploads_size: 103.37 KB (105850 bytes)
themes_path: /var/www/html/wp-content/themes
themes_size: 44.76 MB (46934953 bytes)
plugins_path: /var/www/html/wp-content/plugins
plugins_size: 9.51 MB (9971946 bytes)
fonts_path: /var/www/html/wp-content/uploads/fonts
fonts_size: directory not found
database_size: 2.08 MB (2179072 bytes)
total_size: 322.89 MB (338578298 bytes)

### wp-dropins (1) ###

object-cache.php: true

### wp-active-theme ###

name: Twenty Twenty-Five (twentytwentyfive)
version: 1.0
author: the WordPress team
author_website: https://wordpress.org
parent_theme: none
theme_features: core-block-patterns, post-thumbnails, responsive-embeds, editor-styles, html5, automatic-feed-links, widgets-block-editor, block-templates, post-formats, editor-style
theme_path: /var/www/html/wp-content/themes/twentytwentyfive
auto_update: Disabled

### wp-themes-inactive (14) ###

Twenty Eleven: version: 4.8, author: the WordPress team, Auto-updates disabled
Twenty Fifteen: version: 3.9, author: the WordPress team, Auto-updates disabled
Twenty Fourteen: version: 4.1, author: the WordPress team, Auto-updates disabled
Twenty Nineteen: version: 3.0, author: the WordPress team, Auto-updates disabled
Twenty Seventeen: version: 3.8, author: the WordPress team, Auto-updates disabled
Twenty Sixteen: version: 3.4, author: the WordPress team, Auto-updates disabled
Twenty Ten: version: 4.3, author: the WordPress team, Auto-updates disabled
Twenty Thirteen: version: 4.3, author: the WordPress team, Auto-updates disabled
Twenty Twelve: version: 4.4, author: the WordPress team, Auto-updates disabled
Twenty Twenty: version: 2.8, author: the WordPress team, Auto-updates disabled
Twenty Twenty-Four: version: 1.3, author: the WordPress team, Auto-updates disabled
Twenty Twenty-One: version: 2.4, author: the WordPress team, Auto-updates disabled
Twenty Twenty-Three: version: 1.6, author: the WordPress team, Auto-updates disabled
Twenty Twenty-Two: version: 1.9, author: the WordPress team, Auto-updates disabled

### wp-plugins-active (10) ###

Embed Optimizer: version: 0.4.1, author: WordPress Performance Team, Auto-updates disabled
Enhanced Responsive Images: version: 1.4.0, author: WordPress Performance Team, Auto-updates disabled
Image Placeholders: version: 1.2.0, author: WordPress Performance Team, Auto-updates disabled
Image Prioritizer: version: 0.3.1, author: WordPress Performance Team, Auto-updates disabled
Modern Image Formats: version: 2.5.0, author: WordPress Performance Team, Auto-updates disabled
Optimization Detective: version: 1.0.0-beta1, author: WordPress Performance Team, Auto-updates disabled
Performance Lab: version: 3.8.0, author: WordPress Performance Team, Auto-updates disabled
Speculative Loading: version: 1.4.0, author: WordPress Performance Team, Auto-updates disabled
Web Worker Offloading: version: 0.2.0, author: WordPress Performance Team, Auto-updates disabled
WordPress Importer: version: 0.8.3, author: wordpressdotorg, Auto-updates disabled

### wp-plugins-inactive (1) ###

Hello Dolly: version: 1.7.2, author: Matt Mullenweg, Auto-updates disabled

### wp-media ###

image_editor: WP_Image_Editor_Imagick
imagick_module_version: 1691
imagemagick_version: ImageMagick 6.9.11-60 Q16 aarch64 2021-01-25 https://imagemagick.org
imagick_version: 3.7.0
file_uploads: 1
post_max_size: 1G
upload_max_filesize: 1G
max_effective_size: 1 GB
max_file_uploads: 20
imagick_limits: 
	imagick::RESOURCETYPE_AREA: 122 MB
	imagick::RESOURCETYPE_DISK: 1073741824
	imagick::RESOURCETYPE_FILE: 786432
	imagick::RESOURCETYPE_MAP: 512 MB
	imagick::RESOURCETYPE_MEMORY: 256 MB
	imagick::RESOURCETYPE_THREAD: 1
	imagick::RESOURCETYPE_TIME: 9.2233720368548E+18
imagemagick_file_formats: 3FR, 3G2, 3GP, AAI, AI, APNG, ART, ARW, AVI, AVIF, 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, DPX, DXT1, DXT5, EPDF, EPI, EPS, EPS2, EPS3, EPSF, EPSI, EPT, EPT2, EPT3, ERF, FAX, FILE, FITS, FRACTAL, FTP, FTS, G3, G4, GIF, GIF87, GRADIENT, GRAY, GRAYA, GROUP4, H, HALD, HDR, HEIC, 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, MTV, MVG, NEF, NRW, NULL, ORF, OTB, OTF, PAL, PALM, PAM, 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, TEXT, TGA, THUMBNAIL, TIFF, TIFF64, TILE, TIM, TTC, TTF, TXT, UBRL, UBRL6, UIL, UYVY, VDA, VICAR, VID, VIDEO, VIFF, VIPS, VST, WBMP, WEBM, WEBP, WMV, WPG, X, X3F, XBM, XC, XCF, XPM, XPS, XV, XWD, YCbCr, YCbCrA, YUV
gd_version: bundled (2.1.0 compatible)
gd_formats: GIF, JPEG, PNG, WebP, BMP, AVIF
ghostscript_version: 10.00.0

### wp-server ###

server_architecture: Linux 5.15.49-linuxkit aarch64
httpd_software: Apache/2.4.62 (Debian)
php_version: 8.2.27 64bit
php_sapi: apache2handler
max_input_variables: 1000
time_limit: 30
memory_limit: 128M
admin_memory_limit: 256M
max_input_time: -1
upload_max_filesize: 1G
php_post_max_size: 1G
curl_version: 7.88.1 OpenSSL/3.0.15
suhosin: false
imagick_availability: true
pretty_permalinks: true
htaccess_extra_rules: false
current: 2025-02-05T07:34:05+00:00
utc-time: Wednesday, 05-Feb-25 07:34:05 UTC
server-time: 2025-02-05T07:34:04+00:00

### wp-database ###

extension: mysqli
server_version: 11.4.4-MariaDB-ubu2404
client_version: mysqlnd 8.2.27
max_allowed_packet: 16777216
max_connections: 151

### wp-constants ###

WP_HOME: http://localhost:8888
WP_SITEURL: http://localhost:8888
WP_CONTENT_DIR: /var/www/html/wp-content
WP_PLUGIN_DIR: /var/www/html/wp-content/plugins
WP_MEMORY_LIMIT: 40M
WP_MAX_MEMORY_LIMIT: 256M
WP_DEBUG: true
WP_DEBUG_DISPLAY: true
WP_DEBUG_LOG: false
SCRIPT_DEBUG: true
WP_CACHE: false
CONCATENATE_SCRIPTS: undefined
COMPRESS_SCRIPTS: undefined
COMPRESS_CSS: undefined
WP_ENVIRONMENT_TYPE: local
WP_DEVELOPMENT_MODE: plugin
DB_CHARSET: utf8
DB_COLLATE: undefined

### wp-filesystem ###

wordpress: writable
wp-content: writable
uploads: writable
plugins: writable
themes: writable
fonts: not writable

Thank You,

[westonruter]

cc @adamsilverstein

[adamsilverstein]

Hi @hbhalodia -

Can you confirm you are using the modern image formats plugin and have AVIF output enabled? it does seem odd that you are getting jpeg output as your server clearly supports AVIF.

Also, can you try the same test, but will all plugins disabled so we can see how the default behavior of WordPress is?

[hbhalodia]

Hi @adamsilverstein, as shown in site health information here - #1836 (comment), Modern Image Formats plugin is activated and has AVIF output enabled. [see below screenshot].

Further, I disabled all the plugin and run the test and found the same, it has a fallback JPG in srcset attribute. [see below screenshot]