What actually happens when you upload to WordPress
Each upload spawns multiple copies: WordPress generates thumbnail, medium, large and often theme-specific sizes — commonly 4–8 files per image. Upload a bloated 8 MB photo and every derivative inherits the problem, multiplying storage, backup size and CDN costs.
WordPress also silently scales images above 2560 px (the "big image threshold") — proof that oversized originals are so common the core team built a safety net. Compressing before upload beats plugin-based fixing after: the original is lean, every generated size is lean, and you're not paying a plugin to re-crunch on the server.
Pre-upload checklist for WordPress images
| Setting | Recommendation | Why |
|---|---|---|
| Max width | 2560 px (this preset) | Matches WP’s own threshold; plenty for any theme |
| Format | WebP | WP supports WebP uploads since 5.8; smallest at equal quality |
| Quality | 78–82 | Visually clean; keeps derivatives small too |
| File name | descriptive-with-hyphens.webp | Filenames feed image SEO |
| Before hitting Publish | Fill the alt text field | Accessibility + image search rankings |
Upload limit errors? Many hosts cap uploads at 2–8 MB. Compressed here first, virtually any photo fits without touching php.ini.