PNG to WebP
Convert PNG images to WebP for up to 30% smaller files with no visible quality loss. Perfect for web performance, CDNs, and faster page loads. Completely private.
Convert PNG to WebPNo signup · No uploads · Runs in your browser
What Is WebP?
WebP is a modern image format developed by Google, first released in 2010 and now the recommended format for web images by Google's Lighthouse performance auditing tool. WebP achieves smaller file sizes than both PNG and JPEG by using more sophisticated compression algorithms: block-based prediction coding for lossy compression and a combination of LZ77, Huffman coding, and color cache for lossless compression.
For lossless compression (which is the relevant mode when converting from PNG), WebP is typically 25–35% smaller than the equivalent PNG file. For lossy compression (similar to JPEG but better), WebP is typically 25–34% smaller than JPEG at equivalent visual quality. These gains compound: a website that converts all its PNG and JPEG assets to WebP can reduce total image payload by 30–40%, which translates directly into faster page loads and lower bandwidth costs.
WebP supports transparency (alpha channel) just like PNG, making it a true drop-in replacement for PNG in contexts where the alpha channel is required — logos on transparent backgrounds, UI elements with soft shadows, product photos with clipped backgrounds.
Why Convert PNG to WebP?
The primary reason to convert PNG to WebP is web performance. Images are typically the largest component of a web page's total transfer size — often 60–80% of total page weight. Switching to WebP is one of the highest-leverage optimizations available for Core Web Vitals scores, particularly Largest Contentful Paint (LCP), which Google uses as a ranking factor.
Typical size reduction: PNG → WebP (lossless)
Beyond page speed, CDN bandwidth costs scale directly with image file sizes. A high-traffic website serving millions of image requests per month can see meaningful cost reductions by switching asset delivery from PNG to WebP, often without any change to the serving infrastructure beyond configuring Content-Type headers.
How WebP Compression Works
When converting a PNG to WebP in lossless mode, WebP applies several compression techniques that PNG's DEFLATE algorithm does not use:
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Predictor coding. The image is divided into blocks of pixels. For each block, a predictor selects the most likely value of each pixel based on its neighbors, then only the prediction error is stored. PNG also uses prediction filters, but WebP's block-based approach adapts the predictor per region rather than per scanline.
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Color space transform. WebP can transform the color space of the image before encoding to reduce entropy (randomness) in the data. Correlated color channels (common in natural images and illustrations) compress far better after this transform.
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Color cache and palette coding. Frequently occurring colors in an image are stored in a local cache and referenced by index rather than repeated in full. This is particularly effective for illustrations with a limited color palette, where the same RGB values appear in many non-contiguous regions.
Browser Support and Compatibility
WebP is now supported across all modern browsers. The last major holdout — Safari — added full WebP support in Safari 14 (released September 2020 with macOS Big Sur and iOS 14). As of 2024, global WebP browser support exceeds 97%.
Chrome
Since v32 (2014)
Firefox
Since v65 (2019)
Safari
Since v14 (2020)
Edge
Since v18 (2018)
iOS Safari
Since iOS 14 (2020)
Chrome Android
Since v32 (2014)
The main compatibility gap is older email clients. Most email clients — including Outlook on Windows — do not support WebP in HTML emails. If your converted images will be used in email campaigns, keep them as PNG or JPEG. For all web and app contexts, WebP is a safe, modern choice.
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Open the EditorFrequently Asked Questions
Is WebP supported in all browsers?
Yes. As of 2024, WebP is supported in all major modern browsers including Chrome, Firefox, Safari (since iOS 14 / macOS Big Sur in 2020), Edge, and Samsung Internet. Global support exceeds 97%. The only notable gaps are Internet Explorer (end-of-life since 2022) and some older email clients like Outlook on Windows.
How much smaller will my WebP file be compared to the PNG?
For lossless conversion (the default when converting from PNG), WebP files are typically 25–35% smaller than the source PNG. Results vary by content type: flat-color illustrations and icons with transparency see the largest gains. Complex photographic content stored as PNG sees smaller but still meaningful reductions. Lossy WebP conversion can achieve 60–80% size reduction at the cost of some quality.
Does WebP support transparency like PNG?
Yes, WebP fully supports an alpha transparency channel, both in lossless and lossy modes. Lossless WebP with transparency is a true drop-in replacement for PNG with transparency. Lossy WebP with transparency is useful for product photos with clipped backgrounds where some quality loss in the image detail is acceptable but the transparency edge must remain sharp.
Should I use WebP or AVIF?
AVIF (based on the AV1 codec) achieves even better compression than WebP — typically 50% smaller than JPEG and 20% smaller than WebP at equivalent quality. However, AVIF encoding is very slow, browser support is slightly lower (92% vs 97%), and the format is not yet supported in some older devices. For most web projects today, WebP is the practical choice. AVIF is worth considering for image-heavy sites serving large photographic content where encoding time is not a constraint.
Can I convert PNG to WebP for use in CSS backgrounds and img tags?
Yes. WebP works in <img> tags, CSS background-image, picture elements with srcset, and anywhere a standard image URL is accepted. For progressive enhancement, you can use <picture> with a WebP source and a PNG fallback: <picture><source srcset="image.webp" type="image/webp"><img src="image.png" alt="..."></picture>. Modern browsers will select the WebP; older ones fall back to PNG.