Convert one PNG to WebP, adjust the quality and compare the actual file sizes. The result is not always smaller. The preview shows your source PNG; download and open the WebP to check its appearance. Quality 100 does not guarantee lossless encoding.
PNG vs WebP comparison
| Property | PNG | WebP |
|---|---|---|
| File size | Original file | Measured after conversion |
| Dimensions | Source width and height | Same width and height |
| Quality control | Original file unchanged | Slider from 1 to 100 |
| Preview | Source PNG displayed | Open the downloaded file to inspect |
Convert PNG to WebP with a quality setting
Choose one PNG to convert at its original dimensions. Adjust the quality slider and compare the original and converted file sizes. The size change depends on the image, the setting and your browser; a WebP file can be larger than its source. Processing takes place in your browser without uploading the image.
How to convert PNG to WebP
- Choose or drop one PNG file.
- Adjust the quality slider and wait for conversion to finish.
- Compare the PNG and WebP sizes shown below the source preview.
- Download the WebP and open it to check the result.
When to use this converter
- Create a WebP version of a PNG for a website that accepts WebP.
- Compare file sizes at different quality settings before choosing an export.
- Prepare a separate web version while keeping your original PNG.
Frequently asked questions
Will the WebP always be smaller?
No. The tool measures both files and shows either a saving or an increase. There is no fixed reduction percentage.
Does quality 100 mean lossless?
No lossless guarantee is provided. The slider passes a quality value to the browser encoder; this tool does not offer a separate lossless mode.
What does the preview show?
It shows the source PNG. Download and open the WebP to inspect the encoded result before publishing or replacing an image.
What if my browser cannot encode WebP?
The tool checks for WebP encoding support and displays a warning if it is unavailable. It does not install a fallback encoder; use a browser with WebP encoding support.
Can I convert several PNGs at once?
This page converts one PNG at a time. Use Bulk Convert for multiple images.
Check the result before replacing your PNG
The preview shows the source PNG, not the encoded WebP. Download and open the result to inspect text, edges and transparent areas before using it. Keep the original if the converted image does not meet your needs. Quality 100 is a quality setting, not a guarantee of lossless encoding: this tool has no separate lossless mode.
- One PNG at a time, at its original dimensions
- Quality slider from 1 to 100
- Original and converted file sizes with the actual size difference
- Download the converted WebP without overwriting the source
Free. No signup. No file uploads. Ads via AdSense (consent required).
Sources (1)
- WHATWG (live). HTML Living Standard — HTMLCanvasElement.toBlob(). html.spec.whatwg.org/#dom-canvas-toblob-dev — browser encoding API used by this converter.
These are the W3C, ISO/IEC, ITU-T, and IETF specifications the tool implements or builds on. Locate them on w3.org, iso.org, itu.int, or datatracker.ietf.org.
Related guides
- Image Compression for Core Web Vitals — What Actually Moves the NeedleThe image optimization changes that actually improve LCP, CLS, and INP — with real numbers. Skip the myths, ship the ones that move scores.
- PNG vs JPG vs WebP — A Practical Decision TreeStop guessing which format to use. A real decision tree for PNG, JPG, and WebP based on content type, transparency, and delivery constraints.
- WebP vs AVIF in 2026 — Which to Use and WhenWebP and AVIF are both worth shipping in 2026, but they solve different problems. Here's the practical comparison — compression, support, encode speed, fallbacks.