Need a WebP copy of a picture?

A WebP copy isn't always smaller: a screenshot can shrink a lot, while a photo that's already a JPG may barely change. FluffyBench's WebP converter makes the copy right on your device, lets you choose Lossy or Lossless and the Quality, and shows the size before you save.

FluffyBench · 9 min read · Reviewed October 15, 2026

Can the place you're sending it open WebP?

WebP is a picture format made for websites. Many sites and apps open it, but some upload forms still accept only JPEG or PNG, so check before you convert a whole folder. For apps and browsers, our format compatibility guide shows how to check.

The upload form's list of accepted file types, or its help page, gives you the answer.

Two example upload forms: one accepts JPG, PNG and WebP, so you make the WebP in FluffyBench; the other accepts only JPG and PNG, so you make the format it asks for. — Example lists for illustration. How we reviewed

Lossy or lossless: which WebP do you need?

WebP gives you two ways to pack a picture. Think of packing a suitcase: Lossy leaves behind a few things you probably won't miss, while Lossless packs every item exactly. In FluffyBench's WebP converter, that's the Compression setting. As a rule of thumb, choose Lossy for photos, and Lossless for screenshots, text and logos.

Here's why, with a photo, a screenshot and a transparent graphic, each converted both ways at the starting settings.

Photo

Original JPG: 215.3 KB
Lossy WebP: 209.6 KB
Lossless WebP: 715.0 KB

Screenshot

Original PNG: 35.2 KB
Lossy WebP: 31.5 KB
Lossless WebP: 16.1 KB

Transparent graphic

Original PNG: 2.9 MB
Lossy WebP: 482.5 KB
Lossless WebP: 2.0 MB

The photo barely shrank with Lossy, and Lossless made it more than three times bigger: a photo is full of fine, uneven detail, and an exact copy has to store all of it. The screenshot went the other way. Its flat colors and repeated shapes pack neatly, so the Lossless copy was less than half the size of the original PNG. The transparent graphic shrank the most with Lossy, to about a sixth of its size. Each group has its own scale, so compare each WebP with its own original.

Does the Lossy copy look worse? Here's the same patch of the mountain photo in all three files.

Whole Denali photograph with the compared mountain region marked. — The Lossy copy is hard to tell apart from the original. Enlarged matched crops; sizes are for the complete files. · Photo: NPS Photo / Tim Rains, Public domain, via National Park Service.

Snowy mountain detail in the original JPG. — The Lossy copy is hard to tell apart from the original. Enlarged matched crops; sizes are for the complete files. · Photo: NPS Photo / Tim Rains, Public domain, via National Park Service.

Small text is where Lossy shows. Here's the same word from the screenshot: Lossy dulls the colored fringes around the letters, while Lossless keeps them.

Whole FluffyBench screenshot with the compared lettering marked. — Enlarged matched crops; sizes are for the complete files. Here Lossless was both exact and the smallest.

Interface lettering in the original PNG screenshot. — Enlarged matched crops; sizes are for the complete files. Here Lossless was both exact and the smallest.

Will the WebP be smaller than your picture?

Not always. Two things decide the size: what's in the picture, and the Quality number that Lossy uses. Quality starts at 92, which keeps almost all the detail. A photo that's already a JPG has been compressed once, and at 92 the WebP keeps nearly everything that's left, so the file stays about the same size: the mountain photo above saved just 2.6%, and a batch of 1,000 files we converted at the starting settings came out about 12% bigger overall. A lower Quality is what makes a photo lighter.

Here's the same patch of the mountain photo at four Quality settings, starting from 92, with each whole file's size.

Here's where these controls are in Settings: Compression, then the two controls that only Lossy uses.

Step 1. Lossy drops a little detail, and Quality decides how much.
1. Lossy is the starting choice.
Step 2. With Lossy, Quality trades detail for size. Lower numbers make smaller files.
1. 92 is the starting value.
2. Drag left for a smaller file.
Step 3. Optional, Lossy only: enter an upload's size cap and FluffyBench lowers Quality only as far as needed.
1. Turn on Limit each file's size.
2. Type the cap in KB per file.
Step 4. Lossless keeps every pixel. Quality and Limit each file's size disappear, because there's nothing to trade.
1. Lossless keeps every pixel.
2. Size comes next: Quality and the size limit are gone.

What about transparent or animated pictures?

Transparent backgrounds come through in both modes. Here's the edge of a transparent Earth graphic on a checkerboard: the checks show through beside the planet in each copy.

Whole transparent Earth graphic with the compared edge marked. — Enlarged matched crops on a checkerboard; sizes are for the complete files. · Photo: NASA, Public domain, NASA-created image, via Wikimedia Commons.

Earth's edge and the see-through space beside it in the original PNG. — Enlarged matched crops on a checkerboard; sizes are for the complete files. · Photo: NASA, Public domain, NASA-created image, via Wikimedia Commons.

For a moving GIF or WebP, the Animated images setting decides what you get.

Step 1. Animated images decides what happens to a moving GIF or WebP.
1. Keep the animation, or pick Still of frame 1.

Keep the animation carries the frames into an animated WebP. Still of frame 1 saves just the first picture.

Three rows of mule poses: the animated GIF's frames, the same frames in an animated WebP, and frame 1 alone as a still WebP. — Frames from Muybridge's Kicking Mule, shown for illustration. · Photo: Eadweard Muybridge, Public domain in the United States, via Wikimedia Commons.

FluffyBench keeps animations of up to 500 frames and 64 million frame pixels in total, and Limit each file's size isn't available while an animation is kept. For more on moving pictures, see our animation guide.

Converting to WebP in FluffyBench

Here's the whole job in FluffyBench's WebP converter, from choosing a picture to saving the WebP. If the size readout shows little or no saving, lower Quality and convert again.

Step 1. Choose your pictures. They stay on your device.
1. Choose images opens your file picker.
Step 2. Open Settings and pick Lossy or Lossless. On a phone, tap the gear button again to close it.
1. The gear button (it shows WebP · 92%) opens Settings.
Step 3. Press Convert to make the WebP.
1. Convert 1 to WebP makes the copy.
Step 4. Check the size readout, then press Download to save the WebP. Keep your original.
1. Size before and after converting.
2. Download saves the WebP.
Step 5. With several pictures, Download all (ZIP) saves them together.
1. Download all (ZIP) saves every WebP in one file.

Check your WebP before you use it

Before you upload or send it, open the saved WebP once. FluffyBench's Image Viewer shows the picture on a checkerboard and lists its format and size in pixels.

Step 1. Open the saved WebP. The checkerboard shows through see-through areas.
1. Check the picture and its edges.
2. Image info opens the file details.
Step 2. Image info confirms the format and pixel dimensions.
1. Format should say WebP.
2. Dimensions match the original unless you changed Size.
3. Done returns to the picture.

Then try it in the place it's going.

When WebP isn't the right result

The destination asks for JPEG

FluffyBench's JPG converter

Makes the photo format it requests; JPG fills see-through areas with a color.

You need PNG or an exact working copy

FluffyBench's PNG converter

Keeps every pixel and transparency for editors and forms that ask for PNG.

You need the smallest file, and the format doesn't matter

FluffyBench's Image Space Saver

Finds a resize and quality that fit the file size you set, in the format you pick.

The destination takes AVIF

FluffyBench's AVIF converter

Makes an AVIF copy when the destination asks for that newer format.

An app won't play animated WebP

FluffyBench's GIF converter

Makes an animated GIF for apps that only play GIF animations.

Lossless also has a size limit: about 128 million pixels on a computer and 96 million on a phone. Above it, the converter refuses the picture, so make it smaller with Size in Settings or choose another format.

A failed WebP tile with Details open: the image is too large to save as lossless WebP (134.6 megapixels; the limit is about 128 megapixels). Choose another format or resize it first. — Press Details on a failed tile to read the whole message: the picture's size, the limit, and what to do.

How we measured

Date: October 15, 2026. Browser: Google Chrome 155.0.8059.40. Device: Windows 11 Pro; AMD Ryzen 9 5950X (16 cores); 32 logical processors; 127.9 GiB RAM.

Lossy samples used the converter's default settings (Quality 92); Lossless samples used Compression set to Lossless. The batch of 1,000 files used the default WebP setting, with the ZIP download selected while it ran. The walkthroughs and Image Viewer frames are fresh captures of the current controls, not new measurements. The Quality 80, 70 and 50 copies of the Denali photo were rendered for illustration through the current converter (Quality 92 reproduced the measured file byte for byte); their sizes come from the saved files and aren't a benchmark.

A National Park Service photo of Denali (already a JPG), a FluffyBench screenshot (PNG) and a transparent NASA Earth graphic (PNG). The matched crops come from those exact source files and the saved WebP outputs; the Earth crops are shown on a checkerboard. The animation strip uses frames from Muybridge's Kicking Mule; in our animation guide, a WebP made with Keep the animation kept all 8 frames of the mule. The size-limit screenshot uses a generated single-color PNG of 11600 × 11600 pixels.

File sizes use decimal KB, MB and GB (1 KB = 1,000 bytes), the same as the converter's readout and its KB per file box. Image Viewer lists file size in KiB (1,024 bytes). Exact byte counts are in the chart labels.

Batch result: we converted 1,000 files at once with the default setting. All 1,000 files converted, and the pictures went from about 3.5 GB to about 3.9 GB, roughly 12% bigger (ZIP archive bytes excluded). The batch wasn't sorted by kind of picture, so it doesn't show which files grew.

Pixel checks compare every decoded color and transparency value. Lossless copies matched the photo and the screenshot exactly. The transparent Earth's Lossless copy differed at 12,627 of 1,630,720 pixel positions (under 1%); a changed value doesn't by itself say how visible the change is.

With Limit each file's size, the converter tries up to 6 Quality settings to fit the cap. For some larger photo batches it can use a bundled WebP encoder in a background browser thread; pictures are converted in the browser and aren't sent to a server.

Measured during normal machine use; results describe these runs, not a guarantee.

The measured build was identified from the latest successful Build workflow on main, checked before and after the run.

Image credits

Mount McKinley, viewed from near Stony Dome — NPS Photo / Tim Rains. Public domain. Resized and converted to WebP; callouts remain HTML.
The Earth seen from Apollo 17 with transparent background — NASA. Public domain, NASA-created image. Resized and converted to WebP from the pre-existing transparent derivative; alpha is retained for the checkerboard and dark-surface figure.
Selected frames from the Kicking Mule animation — Eadweard Muybridge. Public domain in the United States. A FluffyBench-owned SVG arranges four credited source-frame thumbnails in playback order with first-party arrows and labels.

WebP converter

Convert to

Common

Icons and print

Game textures

Legacy and specialist formats

Need a WebP copy of a picture?

Can the place you're sending it open WebP?

Lossy or lossless: which WebP do you need?

Photo

Screenshot

Transparent graphic

Original JPG

Lossy WebP

Lossless WebP

Original PNG

Lossy WebP

Lossless WebP

Will the WebP be smaller than your picture?

Original JPG

Quality 92

Quality 80

Quality 70

Quality 50

What about transparent or animated pictures?

Original PNG

Lossy WebP

Lossless WebP

Converting to WebP in FluffyBench

Check your WebP before you use it

When WebP isn't the right result

The destination asks for JPEG

You need PNG or an exact working copy

You need the smallest file, and the format doesn't matter

The destination takes AVIF

An app won't play animated WebP