Drop your files
JPG, PNG and existing WebP all accepted in the same batch.
Convert JPG and PNG to WebP in bulk
WebP is 25–35% smaller than JPEG at equal quality. Convert up to 20 images per batch, entirely on your own machine.
Drop images here
or · JPG, PNG, WebP, GIF
How it works
Choose WebP as the output
Set the format dropdown to WebP. Keep the original dimensions, or cap them for extra savings.
Download the ZIP
Every image converts in-browser. You get a size comparison for each file.
Questions
Why convert to WebP at all?
Every modern browser supports WebP, and files are typically 25–35% smaller than JPEG at the same visual quality. For a website, that is a direct improvement in load time and Core Web Vitals.
Does WebP support transparency?
Yes. PNG sources with transparency keep their alpha channel in WebP — unlike a JPEG conversion, which would flatten it to white.
Will Safari and iOS open WebP files?
Safari 14 and later, and iOS 14 and later, support WebP natively. Anything older will not.
Is there an upload size limit?
No. Files are read straight from disk by your browser. Nothing is transmitted.
Format comparison for the same photograph
Roughly the same 4000 × 3000 source photo, re-encoded at visually equivalent quality. Numbers vary by image content, but the ranking is stable.
| Case | Value | Why it matters |
|---|---|---|
| JPEG (quality 85) | Baseline reference | The universal fallback. Universally supported, no transparency. |
| WebP (quality 80) | 25–35% smaller than JPEG | Same visual quality, alpha channel supported, supported by every browser since 2020. |
| WebP lossless | 10–30% smaller than PNG | Best choice for logos, icons, screenshots and UI graphics. |
| PNG | Largest of the four | Only justified when you need lossless and must support ancient software. |
| AVIF | 40–50% smaller than JPEG | Better than WebP, but encoding is slow and Safari support only arrived recently. |
| GIF | Worst for stills | Only makes sense for animation. Convert still GIFs to WebP or PNG. |
Five mistakes that waste the most time
Converting everything to WebP and losing the fallback
Safari below 14 and old Android WebViews cannot read WebP. If you serve images to a broad audience, keep a JPEG and use a `
` element with both. Using WebP for tiny icons
Below roughly 2 KB, the WebP container overhead can make files larger than an optimised PNG.
Flattening transparency during conversion
Converting a transparent PNG to JPEG turns the background white. Pick WebP or PNG as the output instead.
Expecting the same savings on all content
Photographs shrink 25–35%. Flat illustrations can shrink 70% going from PNG to lossless WebP. Screenshots vary wildly.
Forgetting the extension
A WebP file named `.jpg` will still render in browsers that sniff content, but will break in tools that trust the extension. Upload with the correct name.
Free web version vs the $19 desktop app
| Free, this page | Bulk Image Kit $19 | |
|---|---|---|
| Output formats | JPEG, WebP, keep original | JPEG, WebP, PNG, keep original |
| Alpha channel | Preserved in WebP only | Preserved in WebP and PNG |
| Batch limit | 20 images | Unlimited |
| Quality control | Per batch | Per batch + per image |
| Offline | After first load | Always |
More questions
Does converting to WebP lose quality?
Lossy WebP at quality 80 looks equivalent to JPEG at 85 to almost everyone. If you need zero loss, use lossless WebP — but this browser tool only exposes the lossy encoder.
Can I convert WebP back to JPEG?
Not on this page — the output format options do not include WebP as a source-only path. Any modern browser will decode WebP, so resizing a WebP into a JPEG works fine here.
What about animated WebP?
Only the first frame is captured. The canvas API has no multi-frame support, so animated sources become static images.
Will WebP help my Core Web Vitals?
Yes, directly. LCP is driven by the largest image on the page; 30% fewer bytes on a hero image is a measurable LCP improvement on slow connections.
Need more than 20 at a time?
Bulk Image Kit is the same engine as a single offline file — unlimited images, resize + compress + watermark + rename, one-time $19, no subscription.
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