About this tool
Convert PNG to WebP Free: Lossless and Lossy, Browser-Based
Convert PNG images to WebP format and cut file sizes by 30–70 % without losing transparency or sharpness. WebP is supported by all major browsers and accepted by Google, social platforms, and most modern CDNs. OmegaPix handles the conversion entirely in your browser, drop in your PNGs, choose quality, and download WebP files in seconds, with nothing uploaded to a server.
Why use OmegaPix
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Transparency preserved. No white background added : WebP supports full alpha transparency. Your transparent PNGs convert to transparent WebP files with no background added and no visual change.
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30–70 % smaller than PNG, same visual quality : WebP beats PNG on file size for photographic content, flat graphics, and everything in between: without visible quality loss at standard web quality settings.
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Lossless mode at quality 100 : Set Manual quality to 100 for lossless WebP, pixel-perfect reproduction of the source PNG in a smaller container. Ideal for logos and UI elements.
How it works
Drop your PNG files
Drag PNG images onto OmegaPix. Transparent PNGs (with alpha channel) and opaque PNGs are both fully supported.
Choose WebP output
Select WebP as the output format. Auto quality gives the best size-to-quality ratio. Set Manual quality to 100 for lossless WebP that matches PNG fidelity.
Download WebP files
Each converted file shows its size and savings versus the original PNG. Download individually or export all as a ZIP.
Frequently asked questions
Does PNG to WebP conversion preserve transparency?
Yes. WebP fully supports alpha transparency. When you convert a transparent PNG, OmegaPix produces a WebP file with the same transparency intact. No white or black background is added.
How much smaller will WebP be compared to PNG?
For photographic content, WebP is typically 25–40 % smaller than PNG at equivalent quality. For graphics with large flat-colour regions, savings can reach 50–80 %. Simple line art or icons with few colours may see smaller but still meaningful gains.
Is WebP supported in all browsers?
WebP is supported in Chrome, Firefox, Edge, Safari (version 14+), and Opera. As of 2026, it covers over 97 % of global browser usage. Older iOS versions before 14 do not support WebP.
Can I do a lossless PNG to WebP conversion?
Yes. Set Manual quality to 100. At quality 100, OmegaPix switches to lossless WebP encoding, which preserves every pixel exactly as in the source PNG while typically producing a smaller file.
Does converting PNG to WebP hurt Google image SEO?
No, the opposite. Google recommends serving images in next-generation formats like WebP and rewards pages with smaller, faster-loading images through Core Web Vitals scoring. OmegaPix keeps the original PNG filename base so you can replace images without changing URLs.
Can I batch-convert many PNGs to WebP at once?
Yes. Drop all your PNG files at once and OmegaPix converts them concurrently in separate Web Worker threads. Use the bulk ZIP download to retrieve all WebP outputs in one click.
Should I use WebP or AVIF for new web images?
WebP is the pragmatic choice for maximum compatibility, 97 %+ browser support. AVIF offers 20–30 % better compression than WebP but has slightly lower browser support (around 90 %). If you serve an international audience on diverse devices, start with WebP. Adopt AVIF once your analytics confirm your visitors use modern browsers.
Will WordPress or my CMS accept WebP images?
WordPress has supported WebP uploads since version 5.8 (2021). Most modern CMS platforms, CDNs, and image hosting services accept WebP. If your platform still rejects WebP, check for a plugin update or use the JPEG output option instead.
How does OmegaPix convert PNG to WebP without uploading?
OmegaPix uses libwebp compiled to WebAssembly and loaded directly in your browser. When you drop a PNG, the conversion runs inside a Web Worker thread on your own CPU. The file data never leaves your device.
Can I convert 16-bit PNG to WebP?
Yes. OmegaPix handles 8-bit and 16-bit PNG inputs. The output WebP will be in 8-bit colour depth (standard lossy or lossless), which is sufficient for all web uses. If you need 16-bit precision, keep the original PNG for editing.
When to use this tool
Use WebP for all new web images
WebP has 97 %+ browser support in 2026. It is the best default choice for images on websites, landing pages, and web apps, smaller files, same quality, full transparency support.
Keep PNG for print and editing masters
PNG is lossless and preserves every pixel. Use it as your master file for designs you will re-edit. Distribute WebP versions for web use.
Avoid WebP for email attachments
Many email clients and mobile mail apps do not render WebP correctly. Use JPEG or PNG for images that will be embedded in emails or attached to messages.
When not to use this tool
Pixel art at small sizes
A 32×32 sprite is a single PNG chunk. WebP's container overhead can occasionally make it larger. Keep these as PNG.
Pre-2018 browser audiences
WebP is universally supported in modern browsers but some legacy enterprise / industrial environments are stuck on older versions. PNG is safer there.
Editor round-trips
PNG round-trips losslessly through every image editor. WebP-lossless does too, but some tools auto-downconvert on save. Keep source PNGs for active editing.
Technical details
Why WebP shrinks PNG so much
PNG uses DEFLATE compression over raw pixel data, efficient for line art, weak for photos. WebP-lossless uses dictionary coding plus colour-cache shortcuts and inter-block prediction, finding redundancies PNG's simpler scheme misses. For photographs the gain is huge (50%+ reduction). For tiny line-art graphics the gain is smaller (5-15%) but still positive.
Lossy vs lossless WebP
Lossless WebP is byte-perfect. Your transparent PNG converts to a smaller transparent WebP with identical pixels. Lossy WebP throws away imperceptible detail to shrink further: a photographic PNG converted to lossy WebP at quality 80 is typically 70-85% smaller than the source, looking the same to a viewer. For diagrams, screenshots, and logos: pick lossless. For photos: lossy q80 is almost always the right answer.
Browser support is universal
WebP works in every browser version that's still receiving security updates (Chrome 32+, Firefox 65+, Safari 14+, Edge 18+). The historical "WebP doesn't work in Safari" objection is six years out of date. You can ship WebP as the primary format and serve PNG via picture only if you support pre-2014 browsers.
Real numbers per image type
A 1920×1080 screenshot (lots of UI repeating): PNG 480 KB → WebP lossless 240 KB → WebP q85 110 KB. A 4000×3000 photograph with transparency: PNG 8.4 MB → WebP lossless 5.1 MB → WebP q80 540 KB. A 1080×1080 icon with sharp edges: PNG-8 28 KB → WebP lossless 22 KB.
Your files stay on your device
PNG → WebP conversion runs entirely in your browser via the libwebp WASM encoder. Files are read into memory, transcoded, and offered for download, no upload, no server processing, no third party sees a byte of your image.