PNG to WebP
Convert PNG to WebP in your browser, transparency preserved, files dramatically smaller. Free, private, no upload.
About this tool
PNG files, especially screenshots and graphics with lots of detail, are heavy. WebP keeps the transparency PNG users need while cutting size dramatically, often by half or more. This tool converts PNG to WebP entirely in your browser.
Transparency is preserved, so logos and UI assets survive intact. If you are optimizing a whole site's images, you can batch-drop multiple PNGs and download each converted file.
Common uses
- Compress screenshots and UI images for docs sites and blogs
- Convert transparent logos and icons to a lighter web format
- Reduce page weight without giving up transparency
Automate via API
The same conversion is available as a REST endpoint for scripts, pipelines, and backends. POST the file, get the converted file back:
curl -X POST https://formatably.com/api/v1/tools/png-to-webp \ -H "X-Api-Key: YOUR_API_KEY" \ --data-binary @photo.png \ -o photo.webp
Direct requests accept up to 4 MB; the large-file flow handles up to 100 MB. Both are covered in the API documentation · Get an API key
Using WebP on WordPress, Shopify, and hand-built sites
WordPress: the media library accepts WebP uploads natively since version 5.8 (2021), so you can convert here and upload the .webp exactly like a PNG. For a site with thousands of existing images an auto-conversion plugin makes sense, but for the screenshots and graphics in your posts and pages, converting locally is simpler than installing and trusting another plugin.
Shopify: the platform already serves WebP variants of your product photos through its CDN, so you do not need to pre-convert those. Where converting yourself pays off is theme assets, logo files, and any image you host outside Shopify, such as email graphics or a companion blog.
Hand-built sites: every browser released since 2020 renders WebP, so a plain img tag pointing at the .webp file is safe. You only need the picture-element fallback dance if your audience includes very old corporate browsers.
PNG notes
PNG is the lossless workhorse: screenshots, logos, UI graphics, and anything needing transparency. Every device and program on earth opens it. The tradeoff is size: photos stored as PNG are several times larger than JPEG.
- PNG is lossless, so converting into PNG never loses quality, but converting a photo to PNG can triple its size.
- Transparency is preserved in PNG; JPG has no transparency at all.
WebP notes
WebP is Google's web image format, around 25-35% smaller than JPEG at the same quality, with support for transparency and animation. It is everywhere on the web, and notoriously unwelcome everywhere else: editors, printers, and upload forms.
- Images saved from websites are frequently WebP even when the URL said .jpg.
- Animated WebP needs a format that supports animation on the other side (GIF); converting to PNG or JPG keeps the first frame.
- WebP supports transparency; converting to JPG fills transparent areas with white.
Frequently asked questions
Is transparency kept?
Yes. WebP fully supports alpha transparency, so transparent PNGs convert with their backgrounds intact.
Is any quality lost going from PNG to WebP?
This tool encodes WebP at 90% quality, which is visually indistinguishable from the source for screenshots and graphics while cutting file size dramatically. If you need a pixel-perfect archival copy, keep the original PNG alongside the WebP you serve.
Are my files uploaded to a server?
No. The conversion runs entirely in your browser using WebAssembly and the canvas API; your files never leave your device. There are no ads and no trackers on tool pages. You can verify this yourself: open your browser's developer tools, watch the Network tab while converting, and you will see no upload requests. It even works offline once the page has loaded.
Is there a file size limit?
In the browser there is no hard limit; you are bounded only by your device's memory, and files of a few hundred megabytes are usually fine. The REST API accepts files up to 4 MB in a direct request, or up to 100 MB using the large-file upload flow described in the API docs.
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