Free JPG to WebP Converter

How JPG to WebP conversion works

This tool reads the selected JPG file, decodes it into pixel data with the browser's Canvas API, then re-encodes those pixels as WebP through the browser's built-in image encoder — from file selection to a downloadable WebP file in the same tab, without a server-side upload endpoint for this processing flow.

Decoding a JPG always reads the fully decompressed image the original camera or editor produced; the browser has no way to recover detail the source JPEG already discarded during its own compression. Encoder speed and output size still vary between Chrome, Firefox, Safari, and Edge.

See the tools index for other browser-based conversions, or read how local browser processing works before converting files you consider sensitive.

JPG and WebP compatibility

JPEG (JPG) is the most broadly compatible photo format: cameras, photo libraries, print labs, and social platforms all accept it without exception. WebP is supported in all current desktop and mobile browsers, but some older devices, certain email clients, and some print or desktop-publishing tools still expect JPEG. Neither format supports layered editing; both are flattened export formats rather than editable source files.

See the WebP vs JPG comparison guide for a size and quality comparison. The main converter's image format guide also covers PNG, GIF, SVG, and BMP.

Choosing quality for JPG to WebP

A JPG source file has already been through one round of lossy compression, so some detail is already gone before this tool touches it. Converting it to WebP is a second, independent lossy pass: it cannot restore anything the original JPEG encoder discarded, and stacking two different lossy algorithms can add new artifacts rather than simply repackaging the old ones.

Google's published WebP benchmarks put lossy WebP at roughly 25 to 34 percent smaller than a comparable JPEG at the same SSIM quality score, so re-encoding is usually still worth it for delivery size. High (0.9) keeps additional loss to a minimum for photos you plan to reuse; Recommended (0.75) is a reasonable default for general web delivery. Avoid repeatedly round-tripping the same photo through multiple lossy formats, since each pass compounds the loss.

Batching JPG to WebP conversions

Phone-camera JPG files are typically a few megabytes at 12 to 48 megapixels. Once the browser decodes a file for conversion, a 12-megapixel photo occupies roughly 48 MB of memory regardless of how small the JPG was on disk, because the canvas holds an uncompressed bitmap while re-encoding. Decode memory, not the source file size, sets the practical batch limit.

Start with roughly 50 photos per batch on a laptop and fewer, around 10 to 20, on a phone or tablet, then download the finished batch as a single ZIP archive.

What is JPG?

JPG (or JPEG) is a widely supported lossy format optimized for photos and complex images, balancing quality and file size.

What is WebP?

WebP reduces image file sizes while preserving quality. It supports both lossy and lossless compression and transparency.

Deep Dive: Read our full JPG vs WebP comparison guide.

Frequently Asked Questions

Is the conversion local?

Yes. The conversion uses browser-native image processing. File contents are not intentionally uploaded by this tool.

Can I convert multiple JPG files at once?

Yes, you can drag and drop hundreds of JPG files and convert them all to WebP in one click.

What is the limit?

There is no account-level file count limit. Practical limits depend on your device memory and browser capability.

Which version should I use for sensitive files?

Privacy

Privacy build: This build removes ads, analytics, remote fonts, runtime CDN scripts, and file-operation telemetry. Selected files are processed in the browser using local JavaScript and browser APIs.

Selected images. ConvertUnlimited converts images entirely inside your browser. Selected file contents are processed locally in your browser for this supported workflow. ConvertUnlimited does not provide a server-side upload endpoint for this processing flow. File contents are not intentionally uploaded by this tool.

Contact. For privacy questions, reach out via the project's GitHub.