Image Compressor

Compress Image for Blog Thumbnail (Under 40 KB WebP)

Blog listing thumbnails render at ~ 300 px. Retina 600 px WebP is optimal.

Your images stay on your device. Nothing is uploaded.

Blog category / listing pages typically render post thumbnails at 300 px wide. Uploading at 600 px WebP keeps them retina-crisp and lets a listing page with 20 thumbnails still load under a 1 MB weight budget.

This preset produces a 600 px WebP at quality 80 — thumbnail-optimal.

Frequently asked questions

How much can I shrink images for blog thumbnail?
Typical reductions are 60–85% with no visible quality loss using the defaults on this page. Blog category / listing pages typically render post thumbnails at 300 px wide. Uploading at 600 px WebP keeps them retina-crisp and lets a listing page with 20 thumbnails still load under a 1 MB weight budget.
What format is best for blog thumbnail?
For blog thumbnail the preset above outputs WEBP at quality 80 — the sweet spot for this workflow's LCP and CWV budget.
Will compression break transparency or animation?
Transparency is preserved when the output format supports it (PNG, WebP, AVIF). Animation is preserved for animated WebP. JPEG output flattens transparency to white.
Can I compress dozens of images at once?
Yes — use the bulk compressor. Drop a folder or multi-select files; the queue processes them in order with progress per file, and you can download all results as a ZIP.
Do my images get uploaded anywhere?
No. The tool runs entirely in your browser — important for client work, internal assets, and anything not yet published.

Optimise the rest of your blog thumbnail assets.

Use the bulk compressor to process a folder in one go. Everything runs locally.

Start compressing