Does converting JPG to lossless WebP keep the original quality?

Lossless WebP keeps the exact pixels from the decoded JPG, so no additional quality loss occurs. However, any artifacts already in the JPG remain.

What WebP quality setting should I use for photos?

A quality setting between 75 and 85 is common for photos. This range gives a good balance between small file size and minimal visible loss.

Is WebP always smaller than JPG?

Lossy WebP is usually 25 to 34 percent smaller than a comparable JPEG. Lossless WebP is often larger than the original JPG.

Can I convert JPG to WebP without losing any quality?

You can use lossless WebP to keep the exact decoded pixels, but the file will be larger than the original JPG. The JPG artifacts are still present.

Does Converting JPG to WebP Lose Quality?

Converting a JPG to WebP can add loss, or not, depending on the mode you pick. Lossy WebP decodes the JPG and re compresses it, which introduces a small amount of extra loss. Lossless WebP keeps the decoded pixels exact, but the file usually ends up larger than the JPG you started with. Match the mode to the job. This guide explains what happens to quality in each mode and how to choose settings that fit.

How JPG to WebP Conversion Works

A converter first decodes the JPG into raw pixel data. Then it re encodes that data as WebP. The JPG already carries compression marks from its first encoding. Those marks survive into the WebP file, no matter which mode you choose. The only question is whether the re encoding step adds more loss on top.

Lossy WebP What Happens to Quality

Lossy WebP throws away visual information to shrink the file. Converting a JPG this way means compressing an image that is already compressed. That second pass adds a small amount of loss above the marks the JPG already had. Google reports the result is significantly smaller than a comparable JPEG. The extra loss stays hard to see if you choose a sensible quality value.

Choosing a Quality Value

WebP quality runs from 0 to 100. For photos, values around a moderate to high range work well. A value at the lower end of that range balances clean visuals with a smaller file. Above a certain point, file size grows while visible gains shrink. Below a certain point, the damage starts to show.

Quality in the moderate to high range: Good for photos, small files, minimal visible loss.
Quality in the high to very high range: Larger files, very high fidelity, still adds a little loss next to the JPG.
Quality below a certain point: Smaller files, but the marks become obvious.

Lossless WebP Exact Pixels, Larger Files

Lossless WebP keeps the decoded JPG pixels exactly. No further loss occurs during conversion. The catch is that the JPG's existing compression marks remain. So does the file size problem. Lossless WebP usually comes out larger than the JPG, sometimes a lot larger. Use it only when you need a pixel perfect copy of the decoded image.

JPG vs WebP File Size and Quality Trade Offs

Lossy WebP wins on file size. Google reports lossy WebP files are significantly smaller than comparable JPEGs at the same quality level. That means faster page loads or more images in the same space, with no obvious drop in visual quality. But the JPG's own compression marks carry over. The quality gap between a JPG and a lossy WebP made from it is small. It exists, but you will rarely notice it.

Practical Choices

Keep the JPG. Some apps and email clients still refuse WebP. For sharing widely, JPG stays the safer pick. For the web, where smaller files speed up loading, lossy WebP is the stronger option.

Start from the highest quality source you have. A clean source gives the best WebP result.
Decide whether you need lossless or lossy. If size matters, use lossy with a quality value in the moderate to high range.
Always keep the JPG as a compatibility backup.

How to Choose the Right WebP Quality Value

Pick the quality value by use case. For a website, start at a moderate to high level. Run a few test conversions at different values and judge what looks acceptable. For archival work where size does not matter, lossless WebP preserves the exact decoded pixels. But expect a file larger than the JPG.

Not sure? Start at a moderate value. Compare the output size and look against the JPG. Move up or down based on how much damage you can tolerate and how tight your storage or bandwidth is.

What About Marks from the Original JPG?

Any marks already in the JPG, blockiness or color banding, carry into the WebP. Neither mode removes them. Lossy WebP may add its own marks on top, but a good quality value keeps the extra damage hard to spot. For a clean WebP, start from a higher quality source, such as a PNG or an uncompressed image, rather than a heavily compressed JPG.

When to Use JPG and When to Use WebP

JPG works everywhere. WebP gives smaller files for the web but not universal support. Building a site and want faster images? Convert to lossy WebP at a quality value around a moderate level. Sharing by email or uploading to services that may not accept WebP? Stick with the JPG. You can also keep both: WebP for the site, JPG for sharing.