Convert JPG to WebP in your browser
WebP holds the same picture as a JPG in meaningfully fewer bytes, every current browser can display it, and unlike JPG it keeps transparency. Convert one file or a whole folder, on your own device.
- Nothing is uploaded
- 24–54% smaller in Auto mode
- Keeps transparency
- Unlimited & free
Drop your images here
or paste from the clipboard · ⌘V / Ctrl+V works too
JPG · JPEG · PNG · WebP · AVIF · HEIC · GIF · BMP — no file count limit
Compression settings
Applied to every imageAuto measures each image: it encodes a test pass at several quality levels, scores the result against the original, and keeps the smallest file that still clears a ~40 dB fidelity floor.
Advanced options
Auto applies a halo-free unsharp mask only when an image is scaled below 82%.
Generated in your browser by a synth — no audio file is downloaded, and it stays silent when a batch finishes in a couple of seconds.
WASM codecs are fetched from a public CDN on first use and give slightly smaller files. Every fallback still works offline.
Results
What WebP does better than JPG
WebP is a modern format from the same era as AVIF, built on the video codec work that produced VP8 and VP9. Two comparisons get quoted for it and they disagree, so here are both, measured on our own encoders. Running a 2400×1600 camera JPEG through Auto mode — where the engine finds the lowest quality that still clears a ~40 dB fidelity floor — the saving was 24–54%. Measured the other way round, at equal 40 dB fidelity, WebP came out roughly level with MozJPEG: the lead WebP is usually credited with shows up in perceptual metrics and at lower quality settings, not in PSNR against a strong JPEG encoder. On graphics with flat colour the picture is less ambiguous, because JPG smudges hard edges and WebP does not.
| JPG | WebP | |
|---|---|---|
| Photograph, Auto mode | Baseline | 24–54% smaller (measured) |
| Photograph at matched 40 dB fidelity | Baseline | About level (measured) |
| Flat-colour graphics | Baseline | Clearly smaller |
| Transparency | Not supported | Supported, with alpha |
| Animation | No | Yes |
| Browser support | Universal | Every current browser |
| Older editors and some upload forms | Always accepted | Occasionally rejected |
Where WebP is not the answer
Be honest about the trade-off. WebP is the wrong choice when the file has to open in software you do not control: a client's legacy CMS, a print workflow, a government upload form that whitelists .jpg by extension. It is also pointless if you will re-edit the image repeatedly — every lossy save costs something, so keep a master and export WebP at the end.
And if you want the smallest file that current browsers can read, AVIF usually beats WebP by a further 20–30%, at the cost of noticeably slower encoding.
How the conversion is done here
Your JPG is decoded once, and encoded once to WebP — this is not a re-compression of an already-compressed file, which is what quietly destroys quality in naive converters. In Auto mode the engine measures the image first and chooses the lowest quality that still clears a perceptual fidelity floor, so a smooth sky does not get the same treatment as a hedge full of leaves.
Because everything runs locally, the page never needs to see your image on a server. The optional WebP encoder is a WebAssembly module fetched from a public CDN on first use; if that CDN is unreachable the browser's own WebP encoder takes over, and the conversion still works.
Batch conversion
Drop a whole folder in and the files convert in parallel background workers. On desktop, Download all gives you a single ZIP; on an iPhone the results can be handed to the share sheet so they go straight into your photo library.
Frequently asked questions
Is WebP supported everywhere now?
In browsers, effectively yes — Chrome, Firefox, Safari and Edge have all supported WebP for years, as has iOS since 14. Support in older desktop editors, some print workflows and a minority of upload forms is still patchy, so check what the destination accepts.
How much smaller is WebP than JPG?
It depends which comparison you mean, so here are both from our own measurements. In Auto mode the saving against the original JPG was 24–54%, because the engine picks the lowest quality that still clears a ~40 dB fidelity floor. At matched 40 dB fidelity WebP came out roughly level with MozJPEG — the commonly quoted 25–50% compares WebP against a baseline JPEG encoder rather than MozJPEG, which is what this tool uses. On flat-colour graphics the saving is larger either way, because WebP handles hard edges far better than JPG does.
Does WebP keep transparency?
Yes. WebP stores a full alpha channel, so a transparent PNG converted to WebP keeps its transparency — something JPG cannot do at all, since it flattens transparent areas onto white.
Is converting JPG to WebP lossy?
Yes, both formats are lossy. The image is decoded once from your original and encoded once at high fidelity, so you pay for one generation of loss rather than two. Keep your original JPG as the master and convert the copy you publish.
Are my images uploaded to a server?
No. There is no upload endpoint on this site. The conversion happens in your browser tab, and the only network requests are for the site's own files and the optional WebP encoder module.