How much smaller is WebP than JPG?

On the fixed test image used for every measurement on this site, a 375 KB JPG became a 226 KB WebP — about 40% smaller — at the same default quality. Your results will vary with content: images with large areas of flat colour save more, images full of fine texture save less.

Will converting JPG to WebP lose quality?

Yes, a little, because the JPG must be decoded and re-encoded and WebP is also lossy. At the default quality of 82 the difference is not visible at normal viewing sizes. What you cannot do is recover detail the original JPG already discarded.

Do all browsers support WebP?

Every current browser does, including Safari since 2020. Support is effectively universal now; the only devices that struggle are running very old operating systems.

Should I use WebP or AVIF?

AVIF compresses harder — on the same test image it produced a file 73% smaller than the JPG, against WebP's 40%. WebP encodes much faster and has slightly broader support in older software. If you can serve both with a picture element, do; if you must pick one, WebP is the safer default and AVIF the more aggressive one.

Is my image uploaded to a server?

No. The decode and encode both run in this browser tab, in a Web Worker. The Uploaded readout beside each result measures the page's own outbound network traffic directly, so a successful conversion reads 0 B.

Can I convert a whole folder at once?

You can add as many files as you like in one go. There is no upload, so there is no queue and no per-file cap. The practical ceiling is your device's memory.

Is there a file size limit?

None imposed. Upload limits exist because bandwidth and storage cost money, and neither is involved here.

Does WebP support transparency?

Yes. JPG does not, so a JPG source has no transparency to preserve — but if you later convert a PNG to WebP, its alpha channel survives.

Will there be a watermark?

No. Nothing is added to the image, and there is no paid tier.

Why is my WebP sometimes bigger than the JPG?

It happens when the source JPG was already heavily compressed. WebP then has to spend bits reproducing the JPG's own compression artefacts. If the source is already small and visibly soft, converting it will not help.

Should I keep the original JPG?

Yes, if you might need to re-encode later. Every lossy conversion is one-way, so keeping the best copy you have makes future changes cheaper. Your original file is never modified here.

Does this strip EXIF data like GPS coordinates?

Most metadata is not carried across, which for web images is usually what you want — it removes location data you probably did not intend to publish.

Convert JPG to WebP

Smaller images for your site, without handing them to a server. The conversion runs on your own machine and nothing is uploaded.

ReadyJPG → WEBP

Uploaded0 B

What next

Change the dimensions

How do I convert JPG to WebP?

To convert a JPG to WebP, drop the file onto this page and download the WebP it returns. The conversion runs in your browser, so nothing is uploaded and there is no size limit. On our fixed test image the WebP came out 40% smaller than the JPG at the same default quality, with no visible difference.

How to do it

Open the converter. Open this page in any modern browser. No installation and no account.
Add your JPG files. Drag them onto the panel or click to choose. Add as many as you like — nothing is uploaded, so there is no queue.
Choose a quality. 82 is the default and the right answer for most web images. Move the slider and watch the Smaller by readout to trade size against fidelity.
Download the WebP. Take the file straight to your site. The Uploaded readout shows 0 B, because nothing left the browser.

At a glance

Converts	JPG to WebP
Transparency	Preserved
Compression	Lossy — quality is adjustable, default 82
Where it runs	In this browser tab. The file is not uploaded
File size limit	None imposed — your device memory is the ceiling
Cost	Free
Account needed	No
Watermark	None
Works offline	Usually after first use, but not guaranteed — there is no offline app

What it actually produces

Measured, not estimated. A procedurally generated 2400×1600 (3.8 MP) test image built to carry photographic entropy: value noise across nine octaves down to near-pixel scale, a dense field of small high-contrast features, a smooth gradient, hard edges and light grain. It is not a photograph — it is reproducible, which a photograph is not. Each figure below comes from running that image through this page.

Input	Output	Change
375 KB	226 KB	40% smaller

Your own files will differ — a photograph, a screenshot and a diagram compress very differently. The point of a fixed image is that the formats can be compared with each other, not that your result will match.

Why convert JPG to WebP?

WebP exists for one reason: to make web pages lighter. Google published it in 2010 as a replacement for JPG and PNG, and it now has support in every current browser.

The saving is real and measurable. On the fixed test image used throughout this site, the same source produced a 375 KB JPG and a 226 KB WebP — around 40% smaller, at the same default quality setting, with no visible difference at normal viewing sizes.

On a page with a dozen photographs, that is the difference between a fast site and a slow one.

When should I not use WebP?

Whenever the file leaves your control.

WebP is a web format, and outside the browser its support is patchy. Print shops, older photo editors, plenty of upload forms and some desktop viewers still refuse it. If someone is going to open your file in something you cannot predict, send JPG.

The rule of thumb: WebP for images on a site you control, JPG for images you hand to a person.

WebP or AVIF?

Both are modern, both are well supported, and AVIF compresses considerably harder — the same source as an AVIF came out 73% smaller than the JPG, against WebP’s 40%.

The trade-offs run the other way too. WebP encodes far faster, which matters if you are converting hundreds of images, and it is accepted by slightly more non-browser software.

If your site can serve both from a <picture> element, do that. If you have to choose one, WebP is the conservative pick and AVIF the aggressive one.

Questions

How much smaller is WebP than JPG?: On the fixed test image used for every measurement on this site, a 375 KB JPG became a 226 KB WebP — about 40% smaller — at the same default quality. Your results will vary with content: images with large areas of flat colour save more, images full of fine texture save less.
Will converting JPG to WebP lose quality?: Yes, a little, because the JPG must be decoded and re-encoded and WebP is also lossy. At the default quality of 82 the difference is not visible at normal viewing sizes. What you cannot do is recover detail the original JPG already discarded.
Do all browsers support WebP?: Every current browser does, including Safari since 2020. Support is effectively universal now; the only devices that struggle are running very old operating systems.
Should I use WebP or AVIF?: AVIF compresses harder — on the same test image it produced a file 73% smaller than the JPG, against WebP's 40%. WebP encodes much faster and has slightly broader support in older software. If you can serve both with a picture element, do; if you must pick one, WebP is the safer default and AVIF the more aggressive one.
Is my image uploaded to a server?: No. The decode and encode both run in this browser tab, in a Web Worker. The Uploaded readout beside each result measures the page's own outbound network traffic directly, so a successful conversion reads 0 B.
Can I convert a whole folder at once?: You can add as many files as you like in one go. There is no upload, so there is no queue and no per-file cap. The practical ceiling is your device's memory.
Is there a file size limit?: None imposed. Upload limits exist because bandwidth and storage cost money, and neither is involved here.
Does WebP support transparency?: Yes. JPG does not, so a JPG source has no transparency to preserve — but if you later convert a PNG to WebP, its alpha channel survives.
Will there be a watermark?: No. Nothing is added to the image, and there is no paid tier.
Why is my WebP sometimes bigger than the JPG?: It happens when the source JPG was already heavily compressed. WebP then has to spend bits reproducing the JPG's own compression artefacts. If the source is already small and visibly soft, converting it will not help.
Should I keep the original JPG?: Yes, if you might need to re-encode later. Every lossy conversion is one-way, so keeping the best copy you have makes future changes cheaper. Your original file is never modified here.
Does this strip EXIF data like GPS coordinates?: Most metadata is not carried across, which for web images is usually what you want — it removes location data you probably did not intend to publish.

About these formats

Sources

WebP — an image format for the web — Google
WebP browser support — Can I Use
Image file type and format guide — MDN Web Docs