WebP Resizer — Free Online WebP Resize
Resize a WebP image to exact pixel dimensions or by percentage. Aspect ratio lock, choose output quality. Transparency preserved.
Why resize WebP?
WebP delivers smaller files than JPG or PNG at the same dimensions — but it still pays to serve the actual size you need. A 4K phone photo at 3840 × 2160 pixels is overkill for a 600-pixel-wide blog card. Resizing the WebP down to its display size (or 2× for retina) cuts file weight further and improves Core Web Vitals scores, which directly affects search ranking.
Other reasons to resize: matching exact dimensions for social media platforms (Instagram 1080×1080, Twitter 1200×628), preparing thumbnails, hitting CMS upload size limits, or producing avatars and icons from a single master image.
How this resizer works
The browser decodes your WebP, draws it onto a canvas at the new dimensions using bicubic-style smoothing, and re-encodes it as a fresh WebP at your chosen quality. Transparency is preserved automatically. Nothing is uploaded — everything runs locally using the Canvas API and your browser's native WebP encoder.
Two ways to set the size
- Exact pixel dimensions — type width and height. Lock aspect to avoid stretching.
- Percentage scale — drag the slider. 50% halves, 200% doubles.
Common target sizes for WebP
| Use | Recommended size |
|---|---|
| Hero image (desktop) | 1920 × 1080 |
| Hero image (mobile) | 1080 × 1350 |
| Open Graph preview | 1200 × 630 |
| Card thumbnail | 800 × 600 |
| Profile avatar | 400 × 400 (or 800 × 800 for retina) |
| Blog post inline image | 1200 × 800 |
Upscaling vs downscaling
Downscaling — making the image smaller — looks great. Multiple source pixels get averaged into each output pixel, preserving detail. Upscaling can't add detail that wasn't there; up to 2× is usually fine, beyond that the result gets soft. For dramatic upscales, AI-based tools beat conventional resampling significantly.
FAQs
Will transparency be preserved?
Yes. WebP's alpha channel survives the resize.
Is anything uploaded?
No. Runs in your browser.
What's the maximum output size?
20,000 × 20,000 pixels in theory. Browser memory is the real limit.
How do I avoid stretching?
Keep "Lock aspect" ticked. Editing one dimension auto-updates the other.