Remove client-side media processing feature by adamsilverstein · Pull Request #11309 · WordPress/wordpress-develop

adamsilverstein · 2026-03-19T17:39:52Z

Summary

Removes the wasm-vips client-side media processing feature from WordPress 7.0, punting it to 7.1
The VIPS WASM worker alone adds ~16MB to the build output (~36% of script-modules/), which is too much build size overhead for the current value provided
Removes all PHP functions, REST API endpoints (sideload/finalize), cross-origin isolation infrastructure, VIPS script module handling, build configuration, and associated tests (1,507 lines deleted across 12 files)

Trac ticket: https://core.trac.wordpress.org/ticket/64906

What's removed

7 PHP functions in media.php (client-side media processing, cross-origin isolation, DIP headers)
REST API /sideload and /finalize endpoints and generate_sub_sizes/convert_format params
REST index image processing settings block
Cross-origin isolation output buffering in media-template.php
VIPS script module registration and minified filename handling
VIPS-related build exclusion rules in Gruntfile.js and tools/gutenberg/copy.js
Test file wpCrossOriginIsolation.php and 9 sideload/finalize/generate_sub_sizes tests

What's preserved (independent features)

wp_prevent_unsupported_mime_type_uploads filter (#64836)
X-WP-Upload-Attachment-ID header (error recovery)
Pre-existing post-process and edit endpoints
exif_orientation, filename, filesize, missing_image_sizes schema properties

Test plan

Run phpunit tests/phpunit/tests/media/ — verify no failures
Run phpunit tests/phpunit/tests/rest-api/rest-attachments-controller.php — verify no failures
Run phpunit tests/phpunit/tests/rest-api/rest-schema-setup.php — verify route list is correct
Verify standard image upload via REST API still works with server-side sub-size generation
Run npx grunt build --dev — verify build succeeds
Confirm build/wp-includes/js/dist/script-modules/vips/ no longer exists after build

AI use

I created this PR with careful prompting and planning in Claude Code. I will review the code and test the result.

Commit message

Media: Remove client-side media processing feature.

Punt the wasm-vips client-side media processing feature to a future release. The VIPS WASM worker adds ~16MB to the build output, which is too much build size overhead for the current value provided. Removes all PHP functions, REST API endpoints, cross-origin isolation infrastructure, VIPS script module handling, build configuration, and associated tests.

Props adamsilverstein, jorbin.
Fixes #64906.

github-actions · 2026-03-19T17:40:05Z

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props adamsilverstein, jorbin.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

github-actions · 2026-03-19T17:46:24Z

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aaronjorbin · 2026-03-19T20:08:08Z

I tried to check all of the commits. For the most part, this looks good however I noticed that test_vips_script_modules_always_use_minified_paths wasn't removed. Should that also be removed?

adamsilverstein · 2026-03-19T21:49:13Z

I tried to check all of the commits. For the most part, this looks good however I noticed that test_vips_script_modules_always_use_minified_paths wasn't removed. Should that also be removed?

it should be removed now, I left a "test_vips_script_modules_not_registered_in_core"

adamsilverstein · 2026-03-19T22:03:35Z

Build Size Comparison: vips exclusion

Release zip impact

Zip	Size	Difference from 6.9.1
WordPress 6.9.1 (latest stable)	27 MB	—
Nightly (with vips)	61 MB	+34 MB (+126%)
Nightly without vips	57 MB	+30 MB (+111%)
vips savings in zip		4 MB

The nightly zip is currently 61 MB vs 27 MB for 6.9.1. Removing vips saves 4 MB in the compressed zip (61 MB -> 57 MB). The remaining ~30 MB increase over 6.9.1 comes from other new packages and features in 7.0.

Note: vips is 13 MB uncompressed but compresses to ~4 MB in the zip since the inlined wasm binary is base64-encoded data that still compresses reasonably well.

Full build directory (uncompressed)

Directory	Trunk (before)	PR branch (after)	Savings
`src/` (total)	156 MB	143 MB	13 MB (8%)
`wp-includes/`	87 MB	74 MB	13 MB (15%)
`js/dist/`	41 MB	28 MB	13 MB (32%)

script-modules/ breakdown

Metric	Trunk (before)	PR branch (after)	Savings
`script-modules/` total	15 MB	2.2 MB	12.8 MB (85%)
`script-modules/vips/`	13 MB	gone	13 MB

adamsilverstein · 2026-03-20T03:37:28Z

WordPress 7.0 Build Size Growth Analysis

Overall comparison

Metric	6.9.1	7.0-alpha (nightly)	Delta
Zip file	27 MB	61 MB	+34 MB (+126%)
Uncompressed	81 MB	146 MB	+65 MB (+80%)

Size growth by feature (uncompressed, sorted by impact)

#	Feature	Size added	Category	Core commit
1	Extra bundled themes (nightly build artifact, not shipped in releases)	+34.0 MB	Build artifact	N/A — nightly zips include all `twenty*` themes; releases only ship latest 3
2	vips/wasm client-side media processing	+13.1 MB	New feature	`0544d56`
3	Admin routes/pages (`wp-includes/build/`)	+5.5 MB	New feature (Site Editor routing)	`49d8c11` (new build system)
4	Block-library per-block CSS (new split alongside existing bundled CSS)	+3.0 MB	Architecture change	Via Gutenberg build artifact
5	`editor.js` growth (RTC, new editor features)	+2.0 MB	Feature growth	`19c9957` (RTC endpoints)
6	New script modules (abilities, boot, route, workflow, latex-to-mathml, etc.)	+1.8 MB	New features	Via Gutenberg build artifact
7	`components.js` growth	+1.4 MB	Package growth	Via Gutenberg — new/updated components
8	Icons library (`wp-includes/icons/`)	+1.3 MB	New feature	`5b7a3ad`
9	PHP AI Client (`wp-includes/php-ai-client/`)	+0.9 MB	New feature	`52e3c30`
10	`media-utils.js` growth (media processing)	+0.8 MB	Feature growth	Via Gutenberg — client-side media support
11	New JS packages (sync, theme, upload-media, etc.)	+0.8 MB	New features	Via Gutenberg build artifact
12	`block-editor.js` growth	+0.6 MB	Package growth	Via Gutenberg
13	`block-library.js` growth	+0.5 MB	Package growth	Via Gutenberg — new blocks
14	Editor CSS growth	+0.4 MB	Feature growth	Via Gutenberg
Total accounted		~66 MB

Key takeaways

1. Theme bundling is the #1 factor (+34 MB) — but it's a nightly-only issue

The nightly build includes all 16 twenty* themes (classic + block). WordPress releases only ship the latest 3 (currently twentytwentythree, twentytwentyfour, twentytwentyfive). This accounts for over half the raw delta and is not a concern for actual releases.

2. Adjusting for release packaging, the real growth is ~31 MB

Without the extra themes, the growth is from:

vips/wasm: 13 MB (already addressed in PR #11309)
New build system artifacts: 5.5 MB (admin routes/pages JS)
Per-block CSS split: 3 MB (block styles duplicated in both bundled and per-block formats)
Editor/package growth from Gutenberg: ~8 MB (new features like RTC, abilities, icons, AI client, new components)
Icons + AI client: 2.2 MB (new PHP-side features)

3. Block-library CSS is duplicated

The 7.0 build ships both the old bundled CSS files (960K) and new per-block CSS directories (3 MB). If the bundled files are still the ones loaded, the per-block copies may be unnecessary overhead (or vice versa).

4. Non-minified JS files add significant weight

Non-minified JS in js/dist/ is 21 MB (same as minified + vips). These ship in the zip but are only used in SCRIPT_DEBUG mode. The old build only shipped non-minified; the new build ships both.

New JS packages in 7.0

Package	Minified	Full	Total
sync.js	120K	360K	480K
theme.js	60K	128K	188K
upload-media.js	24K	56K	80K
block-serialization-spec-parser.js	12K	52K	64K
react-i18n.js	4K	4K	8K
undo-manager.js	4K	8K	12K

New script modules in 7.0

Module	Size	Purpose
vips/	13,440K	wasm image processing (plugin-only)
latex-to-mathml/	584K	Math rendering
abilities/	428K	Abilities API
route/	260K	Site Editor routing
workflow/	208K	Editor workflow
boot/	180K	Editor bootstrap
interactivity/ (growth)	148K	Interactivity API
block-library/ (growth)	136K	Block scripts
lazy-editor/	132K	Lazy-loaded editor
connectors/	24K	AI connectors
edit-site-init/	24K	Site editor init
core-abilities/	16K	Core abilities
a11y/ (growth)	12K	Accessibility

Comparison methodology

6.9.1: Downloaded from https://wordpress.org/wordpress-6.9.1.zip (27 MB)
7.0-alpha: Downloaded from https://wordpress.org/nightly-builds/wordpress-latest.zip (61 MB)
Both unzipped to /tmp/ and compared directory-by-directory using du -sk
Commits traced via git log 6.8.1..trunk in wordpress-develop (no 6.9.x tags available)

Punt the wasm-vips client-side media processing feature to 7.1 as it adds ~16MB of WASM to the build without sufficient value for 7.0. Removes all PHP functions, REST API endpoints (sideload/finalize), cross-origin isolation, VIPS script module handling, and associated tests.

Remove extra blank lines before closing braces in register_routes() and wp_print_media_templates().

Missed in the initial removal of the client-side media processing feature.

Remove image_sizes, image_size_threshold, image_output_formats, interlaced settings from REST index, and generate_sub_sizes/convert_format params from media create endpoint.

…les. The previous build config only excluded non-minified vips files, but with client-side media processing removed from Core, vips should not be copied or registered at all. This adds: - `!vips/**` exclusion to the Gruntfile copy task - Skip `vips` directory in `generateScriptModulesPackages()` so vips modules are not auto-registered - Update test to assert vips modules are not registered in Core Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

WP_Script_Modules::$registered is private with no public getter. Use the same enqueue-and-check-output pattern as the original test to verify vips modules are not registered. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The upload-media package in the Gutenberg build artifact declares @wordpress/vips/worker as a dynamic module dependency. Since vips is excluded from Core, this unregistered dependency causes a _doing_it_wrong notice on every admin page load. Filter out @wordpress/vips/* module dependencies during the script-loader-packages.php generation step. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

adamsilverstein · 2026-03-20T16:55:20Z

Gruntfile.js

-						// Skip non-minified VIPS files — they are ~16MB of inlined WASM
-						// with no debugging value over the minified versions.
-						'!vips/!(*.min).js',
+						'!vips/**',


make sure no vips included from GB

github-actions · 2026-03-20T17:11:06Z

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 62081
GitHub commit: c863860

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.

adamsilverstein mentioned this pull request Mar 19, 2026

Gate client-side media processing as plugin-only WordPress/gutenberg#76700

Merged

3 tasks

adamsilverstein and others added 6 commits March 20, 2026 08:55

Fix coding standards errors

a1ebf6d

Remove extra blank lines before closing braces in register_routes() and wp_print_media_templates().

Remove wp_get_chromium_major_version() test file

1b7ee3a

Missed in the initial removal of the client-side media processing feature.

Update wp-api-generated.js fixtures

acc8d4a

Remove image_sizes, image_size_threshold, image_output_formats, interlaced settings from REST index, and generate_sub_sizes/convert_format params from media create endpoint.

adamsilverstein force-pushed the remove-client-side-media branch from 68c4e9a to b8adfe8 Compare March 20, 2026 15:58

adamsilverstein and others added 2 commits March 20, 2026 08:59

Merge branch 'trunk' into remove-client-side-media

2422bf4

adamsilverstein requested review from desrosj and westonruter March 20, 2026 16:52

adamsilverstein commented Mar 20, 2026

View reviewed changes

Merge branch 'trunk' into remove-client-side-media

ccdb6de

github-actions bot closed this Mar 20, 2026

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Remove client-side media processing feature#11309

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Summary

What's removed

What's preserved (independent features)

Test plan

AI use

Commit message

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Build Size Comparison: vips exclusion

Release zip impact

Full build directory (uncompressed)

script-modules/ breakdown

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adamsilverstein commented Mar 20, 2026

WordPress 7.0 Build Size Growth Analysis

Overall comparison

Size growth by feature (uncompressed, sorted by impact)

Key takeaways

1. Theme bundling is the #1 factor (+34 MB) — but it's a nightly-only issue

2. Adjusting for release packaging, the real growth is ~31 MB

3. Block-library CSS is duplicated

4. Non-minified JS files add significant weight

New JS packages in 7.0

New script modules in 7.0

Comparison methodology

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