Convert JPG to WebP — same quality, leaner pages
You already have a library of JPGs. Converting them to WebP trims 25-35% off each file at perceptually identical quality — smaller pages, faster loads, and a lower CDN bandwidth bill. The whole process runs locally in your browser; nothing is uploaded.
Convert to WebP →Why convert JPG to WebP?
JPEG has been the default photo format since 1992 and it still works, but it was designed before modern compression research. WebP uses a DCT-based lossy codec derived from the VP8 video format and consistently achieves 25-35% smaller files than JPEG at the same perceptual quality score. For a site with hundreds of product photos or a blog that accumulates images over years, that gap adds up to real seconds shaved off page load time and real dollars saved on data transfer costs. Browser support is no longer a barrier: Chrome has supported WebP since version 23 (2012), Firefox since 65 (2019), Safari since 14 (2020), and Edge since 18 (2018). In 2026, over 97% of global browser sessions can display WebP without any fallback. Converting your existing JPG library to WebP is the single lowest-friction step you can take to modernize page performance.
What you lose and what you gain
Both JPG and WebP are lossy codecs — each encode discards some image data that cannot be recovered. When you convert JPG to WebP, you are re-encoding already-compressed pixels, not going back to the original RAW. That said, the practical quality loss at WebP quality 75-80 compared to a JPG quality 90 source is below the threshold most people can detect in a side-by-side comparison. What you gain is a 25-35% file-size reduction that browsers and CDNs can deliver noticeably faster. If you need the absolute smallest file and encode speed is not a concern, AVIF would compress another 10-20% beyond WebP — but AVIF encodes 5-10× slower, making it a poor fit for batch pipelines or on-the-fly server-side conversion. WebP hits the sweet spot: meaningfully smaller than JPG, universally supported, and fast enough to encode at scale.
How to convert JPG to WebP
Everything runs locally in your browser — no server, no account, no upload. The page needs to load once; after that it works offline too:
- Click "Convert to WebP →" at the top of this page, or drag your JPG onto the drop zone on the homepage.
- Your browser decodes the JPG natively using its built-in JPEG decoder — the same engine that renders every photo on every website you visit. No extra download is required for this step.
- ConvertMyPic re-encodes the decoded image data to WebP using libwebp compiled to WebAssembly. libwebp is the reference WebP encoder maintained by Google at chromium.googlesource.com/webm/libwebp and is the same library that Chrome uses internally.
- A download button appears as soon as encoding finishes. The output file keeps your original filename with the extension changed to .webp — photo.jpg becomes photo.webp. EXIF metadata is preserved by default.
- Need a different quality or want to strip location data? Open /convert for the advanced view: quality slider (1-100), EXIF-strip toggle, and lossless mode for graphics and screenshots.
File size comparison: JPG vs WebP at various quality levels
Numbers from a real 4032×3024 iPhone 15 Pro photo (12.2 MP, coastal landscape). The JPG source at quality 90 (~1.7 MB) was used as the reference; WebP was encoded at each quality level using libwebp.
| Format | Quality | File size | Visual notes |
|---|---|---|---|
| JPG (source) | 90 | 1.7 MB | Reference — no visible artifacts |
| WebP | 90 | 1.05 MB | Visually identical to source JPG |
| WebP | 75 | 620 KB | Best quality/size balance for most web use |
| WebP | 50 | 340 KB | Slight smoothing in fine textures |
| WebP lossless | — | 3.4 MB | Pixel-perfect; larger than JPG source |
When to convert, and when to stay on JPG
Convert to WebP when you control where the image is displayed: your own website, a headless CMS that accepts any format, a CDN that serves what you upload, or a mobile app built on a modern WebView. WebP will shave meaningful bytes off every request and those savings compound across a full page of images. Stay on JPG when the destination has explicit format requirements you cannot change. Old print kiosks at pharmacies and photo labs almost universally require JPEG and will reject or silently corrupt WebP files. Some legacy corporate CMSes — particularly SharePoint installs that have not been updated since 2018 — whitelist only JPG, PNG, and GIF. Certain corporate email firewalls inspect image MIME types and strip or block image/webp attachments; if your images are going into email, JPG is the safer choice. Social media platforms (Instagram, Facebook, X/Twitter) accept WebP uploads but transcode everything server-side anyway, so the format you upload matters less than you might think. A practical rule: if the pipeline end-to-end is under your control, WebP. If an external system sits between you and the viewer, check its format support first.
Under the hood: which codecs are used
ConvertMyPic is a fork of Google's Squoosh. JPEG decoding is handled by the browser's native image decoder — no extra WASM download needed, and it runs at GPU-accelerated speeds. WebP encoding uses libwebp, the official open-source WebP encoder and decoder published by Google at chromium.googlesource.com/webm/libwebp. The library is compiled to WebAssembly via Emscripten and runs in a Web Worker so the main thread — and your UI — stays responsive during encoding. libwebp implements the full VP8 lossy codec, VP8L lossless codec, and the animated WebP container (VP8X). The WASM module is cached by the service worker after the first page load, which is why subsequent conversions — and offline use — start encoding immediately without any network round-trip.
FAQ
Do my files get uploaded anywhere?
No. The entire conversion runs in your browser using WebAssembly. Open your browser's Network tab during a conversion — you will see zero outbound requests beyond the initial page load. There is no server to upload to.
What is the maximum file size I can convert?
Browser memory is the only limit. 200MP+ photos (over 30MB JPGs) work on desktop Chrome with 16GB of RAM. On mobile, expect stability up to around 40MP. If a file is too large, you'll see a clear error message rather than a crash.
Will the WebP look as good as the original JPG?
At WebP quality 75-80, blind A/B tests consistently place the two images at parity. Skies and smooth gradients handle re-compression particularly well. If you are converting a heavily compressed JPG (quality below 60), start at a higher WebP quality to avoid stacking artifacts.
Does the tool preserve EXIF metadata like GPS and camera info?
Yes, by default. If you are sharing the WebP publicly and want to strip location data, the advanced options on /convert include an EXIF-strip toggle. Privacy-sensitive workflows should turn that on.
Does this work offline?
Once the page has loaded once, the service worker caches the app shell and the libwebp WASM module. Subsequent visits work with no network connection. That's also why it's installable as a PWA on desktop and mobile.
Why is this free?
Because there are no servers to operate. The libwebp WASM module is a few hundred kilobytes, served once from a CDN, and all the compute runs on your CPU. Hosting cost is near zero, so there is nothing to charge for.
Does every browser support WebP in 2026?
All major browsers have supported WebP for several years: Chrome since v23 (2012), Firefox since v65 (2019), Safari since v14 (2020), and Edge since v18 (2018). Global browser support sits above 97%. The only environments where WebP fails are ancient IE, very old iOS (pre-14), and niche embedded browsers.
When would AVIF be a better choice than WebP?
AVIF compresses 10-20% better than WebP at matched quality, and handles high-detail textures and HDR content more gracefully. Choose AVIF when you need the absolute smallest file and you have time to encode — AVIF encodes 5-10× slower than WebP. For batch pipelines, on-the-fly server conversion, or time-sensitive workflows, WebP is the more practical format.
Can I create a lossless WebP for graphics or screenshots?
Yes. Open /convert and enable lossless mode. Lossless WebP is pixel-perfect — no data is discarded — but the files are larger than lossy WebP and often larger than the source JPG too. Lossless mode makes most sense for screenshots, UI mockups, and synthetic graphics, not for photographs. If you're starting from a JPG (which is already lossy), lossless WebP just preserves the JPG's already-degraded pixel values exactly.
Does libwebp support animated WebP output?
The libwebp library itself supports animated WebP via the VP8X container, but ConvertMyPic currently converts still images only. Animated WebP output — for converting GIFs or video clips — is on the roadmap. For now, if you need animated WebP, tools like FFmpeg or Cloudinary handle it well.