Tool facts
- Input and output
- image/webp → image/webp
- Files per operation
- 1
- Total input limit
- 100 MiB
- Processing
- In your browser; no file upload
- Account
- Not required
- Price
- Free
Scope of these facts
- Selected file contents stay in the browser for processing. Loading the website and its separate usage analytics can still use the network.
- Verification covers the declared checks for supported files, not independent certification or acceptance by another portal. A format-signature check is not digital-signature validation.
- JavaScript, the required browser APIs and sufficient device memory are needed. Limits are admission ceilings, not a guarantee for every file, browser or iPhone.
- WebP re-encoding is lossy even for lossless input. Accepted results retain dimensions and decoded alpha, not necessarily RGB values. Animation and unsupported metadata are declined.
How it works
- Select one static WebP image.
- Choose Compress WebP. Local encoding stops at the first smaller candidate within the quality limits.
- Download the verified WebP after format, dimensions and transparency checks.
WebP quality and compression
WebP can store images with lossy or lossless encoding. This tool uses native lossy recompression with quality settings 0.92, 0.88, 0.84 and 0.80, stopping at the first smaller result. These are encoder values, not visual-quality percentages. A lossless source can therefore become lossy; keep your original when exact colors matter.
Static images, not flattened animations
Animated WebP is detected from its container flags and animation chunks before decoding. Animated files are rejected rather than flattened to one frame. Static image width and height remain unchanged, and decoded alpha values are compared exactly before download.
Supported variants and metadata
Simple VP8/VP8L and supported static VP8X images are accepted. Files with ICC color profiles, EXIF, XMP or unknown chunks are currently declined. The browser writes a fresh WebP; original metadata is not retained. Already compact files may not become smaller within the quality limits.
Privacy and mobile limits
Your WebP stays on your device. There is no upload or server-side processing. The current file-size, pixel-count, dimension and Worker limits are shown in the technical facts above. Your browser must support native WebP encoding; unsupported output formats are never substituted.
Frequently asked questions
Does the output stay WebP?
Yes. Its declared type, signature, container and decoded dimensions are verified again. PNG or JPEG fallback output is rejected.
Can I compress animated WebP?
Not in this version. Animation is detected and rejected without removing frames or offering a misleading successful result.
Is transparency preserved?
Yes. Every decoded alpha value is compared before the result is offered. RGB colors can change because recompression is lossy.
Why did my WebP not shrink?
WebP is already an efficient format. If no smaller output is found above the quality floor, the tool reports that honestly and leaves your original untouched.