PNG to WebP Converter
Convert PNG images to WebP instantly in your browser — with SEO-ready alt text auto-generated by AI. Free, no upload required, and works on any device. Google's modern format. ~30% smaller than JPEG at equal quality, with transparency.
Why convert PNG to WebP?
Google's modern format. ~30% smaller than JPEG at equal quality, with transparency. Converting from PNG to WebP is one of the fastest wins for Core Web Vitals — smaller files mean faster Largest Contentful Paint and better Google rankings.
100% in-browser conversion
Your PNG files never leave your device. Conversion happens entirely in the browser using the Canvas API, so it's private, instant, and free — no queue, no watermark, no signup for conversion.
SEO alt text included
Every converted image gets an AI-generated alt tag optimized for screen readers and search engines. Copy it straight into your CMS, no rewriting needed.
How to convert PNG to WEBP
- Open the AltPixel converter.
- Drag and drop your PNG files, or click to browse.
- Set the output format to WEBP.
- Wait ~1 second for conversion (runs in your browser).
- Copy the AI-generated alt text and download the WEBP.
Frequently asked questions
Is this PNG to WebP converter really free?
Yes. Image conversion is 100% free and unlimited — no signup required. Only the optional AI alt-text generation uses credits (5/day free, 2,000/month on Pro).
Will converting PNG to WebP lose quality?
WebP supports lossless encoding, so quality is preserved. AltPixel uses quality 0.9 by default — near-visually-lossless with big size savings.
Does WebP help with SEO?
Yes. Google's PageSpeed Insights and Core Web Vitals reward smaller image payloads. Serving WebP instead of PNG typically drops image weight by 30–70%, directly improving LCP scores and Google rankings.
Can I batch convert multiple PNG files?
Yes — up to 10 files at once. Drop them all on the tool, pick WebP as the output format, and download each result with its AI alt text.
Is WebP supported in all browsers?
WebP is supported in Chrome, Firefox, Safari 14+, and Edge — over 96% of global browsers.