WordPress 7.1 Beta 1 expands client-side media processing for HEIC, UltraHDR, AVIF, WebP, and GIF-to-video conversion, with upload progress and automatic retries. The browser now does more work before the server receives the final asset, so compatibility testing must cover device, browser, format, metadata, output, and failure recovery.
Use this for editorial teams that upload iPhone photos, modern image formats, animated GIFs, large files, or media over unstable connections, especially when optimization, offload, CDN, or metadata plugins are active.
Quick answer
WordPress 7.1 HEIC, AVIF, and WebP Client Media Processing Test should be handled with a narrow evidence-first workflow: build media fixtures, test browser matrix, interrupt and retry, then verify the result before making broader changes.
What to check first
- Prepare synthetic HEIC, UltraHDR, AVIF, WebP, JPEG, PNG, and animated GIF files with known dimensions, color, orientation, metadata, and alt text.
- Upload each fixture in current Chrome, Safari, Firefox, and a supported mobile browser while recording memory, duration, progress, and output format.
- Interrupt the network during processing and transfer, then verify retry resumes safely without duplicate attachments or partial files.
- Inspect original and generated files for orientation, color profile, animation or video behavior, EXIF privacy, dimensions, sizes, and MIME types.
- Retest image optimization, object storage, CDN rewriting, backups, regeneration, REST responses, and media replacement plugins.
Diagnostic table
Use this table to keep the work practical. It connects the symptom to evidence and a verification step.
| Action | Evidence to collect | How to verify |
|---|
| Build media fixtures | Prepare synthetic HEIC, UltraHDR, AVIF, WebP, JPEG, PNG, and animated GIF files with known dimensions, color, orientation, metadata, and alt text. | Every supported format uploads or fails with a useful message and leaves no duplicate or partial attachment. |
| Test browser matrix | Upload each fixture in current Chrome, Safari, Firefox, and a supported mobile browser while recording memory, duration, progress, and output format. | Orientation, color, dimensions, alt text, and expected animation or video behavior remain correct. |
| Interrupt and retry | Interrupt the network during processing and transfer, then verify retry resumes safely without duplicate attachments or partial files. | Generated files return the correct MIME type through origin and CDN. |
| Inspect output files | Inspect original and generated files for orientation, color profile, animation or video behavior, EXIF privacy, dimensions, sizes, and MIME types. | Offload, optimization, backup, REST, and regeneration workflows recognize the resulting attachment. |
Why this usually happens
- Client processing depends on browser codecs, memory, worker support, and device resources before PHP upload limits apply.
- Format conversion can remove, preserve, or reinterpret orientation and metadata differently from server libraries.
- An interrupted request can create an attachment record, file, or retry state at different points in the workflow.
- Optimization and offload plugins may expect the original MIME type or a server-generated intermediate file.
Useful command or data shape
Adapt paths, IDs, and privacy handling to the site before running commands or storing data on production.
wp media list --fields=ID,title,mime_type,width,height,url --format=table
wp attachment meta get 123 _wp_attachment_metadata --format=json
wp media regenerate 123 --yes
curl -sS -I --max-time 15 'https://example.com/wp-content/uploads/2026/07/output.webp'
Safe fix order
Do the work in a sequence that makes each result easy to prove. Stop if a step produces new evidence that changes the incident scope.
- Build media fixtures
- Test browser matrix
- Interrupt and retry
- Inspect output files
- Test plugin pipeline
What to tell the client or owner
Share the fixture name, browser and device, source and output formats, timing, memory symptom, retry result, metadata comparison, and affected media plugin.
Production verification checklist
- Every supported format uploads or fails with a useful message and leaves no duplicate or partial attachment.
- Orientation, color, dimensions, alt text, and expected animation or video behavior remain correct.
- Generated files return the correct MIME type through origin and CDN.
- Offload, optimization, backup, REST, and regeneration workflows recognize the resulting attachment.
Mistakes to avoid
- Do not judge the fix by one browser or the homepage only.
- Do not delete evidence before recording usernames, file paths, timestamps, and response headers.
- Do not add a cache, security, or tracking plugin while the original problem is still unclear.
- Do not leave test users, temporary debug logs, or broad API keys active after verification.
When HandL WP should help
Bring in help when this affects leads, checkout, search visibility, malware risk, paid media reporting, or a client production site. HandL WP can trace the issue through WordPress, hosting, cache, tracking, and Search Console, then verify the workflow after the technical fix.
If this is active on a production site, test WordPress 7.1 media compatibility.
Related HandL WP guides
Use these related guides when the same issue touches tracking, security, checkout, or crawler visibility.
Helpful references