Use JPEG for photos that must open everywhere, PNG for screenshots, logos and anything that needs exact pixels or transparency, and WebP for images on a website, where it usually gives the smallest file for the same look and supports transparency too. Many sites serve WebP with a JPEG or PNG fallback. OpticBatch from Automata Labs converts and resizes whole folders between JPEG, PNG and WebP on your PC, with a quality slider and a live size estimate, and it never overwrites your originals.
Convert a folder to WebP, JPEG or PNG locally, with originals left untouched.
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What is the difference between WebP, JPEG and PNG?
All three are raster formats, meaning they store a grid of pixels. They differ in how they compress that grid and what extra features they carry.
| JPEG | PNG | WebP | |
|---|---|---|---|
| Compression | Lossy | Lossless | Lossy or lossless, your choice |
| Transparency (alpha) | No | Yes | Yes, in both modes |
| Animation | No | Through APNG | Yes |
| Best at | Photographs | Screenshots, logos, line art, text | Website images of every kind |
| Opens everywhere | Practically yes | Practically yes | Modern browsers and many apps, but not every older tool |
Mozilla’s image format guide sums up the trade-off well. It says JPEG “is currently the most widely used lossy compression format for still images” and is “particularly useful for photographs,” but that lossy compression on “content requiring sharpness, like diagrams or charts, can produce unsatisfactory results.” It also notes that JPEG “does not support an alpha channel,” which is why logos with transparent backgrounds are usually PNG.
Is WebP smaller than JPEG and PNG?
Usually, yes. Google, which created WebP, says on its WebP page:
- “WebP lossless images are 26% smaller in size compared to PNGs.”
- “WebP lossy images are 25-34% smaller than comparable JPEG images at equivalent SSIM quality index.”
- Lossless WebP supports transparency “at a cost of just 22% additional bytes,” and Google says lossy WebP with transparency is typically about three times smaller than PNG.
Those are Google’s averages from its own studies, not a promise for every image. Your results depend on the picture, the quality setting and the encoder. A simple rule: convert a sample of your real images at two or three quality levels and compare both the size and the look before you commit a whole library.
Which format should I use for each job?
| Job | Format | Why |
|---|---|---|
| Product and blog photos on your own website | WebP, with JPEG fallback if you support old browsers | Smallest files for the same visual quality |
| Photos you email, print or send to a client | JPEG | Opens in everything, including older software |
| Screenshots, UI captures, diagrams with text | PNG, or lossless WebP on the web | Lossy compression blurs sharp edges and text |
| Logos and icons with transparent backgrounds | SVG if you have it, otherwise PNG or WebP | JPEG cannot store transparency |
| Marketplace or CMS uploads | Whatever the platform asks for | Some platforms still require JPEG or PNG |
| Archive masters | Keep the original | Re-saving a lossy file loses detail each time |
MDN’s own guidance points the same way: for raster images on the web, “prefer WebP or AVIF, which generally provide better compression than PNG, JPEG, and GIF,” and for “screenshots, diagrams, logos, and line art, prefer lossless encoding.” It adds that “JPEG is lossy, so it is often a good fallback format for photographs, while PNG is lossless.”
Do all browsers support WebP?
Current versions of the major browsers do. Google’s WebP FAQ lists lossy, lossless and alpha support in Chrome, Edge, Firefox, Opera and Safari 14 and later (iOS 14 and macOS Big Sur onward). MDN notes that WebP “now has broad support in the latest versions of major web browsers, although it does not have deep historical support.”
If some of your visitors use older systems, serve WebP with a fallback. The HTML picture element lets you list a WebP source and a JPEG or PNG fallback, and the browser picks the first one it can display. Outside the browser, check the tools your recipients use. Some older photo viewers, office software and upload forms still expect JPEG or PNG.
Does converting between formats lose quality?
It depends on the direction:
- PNG to lossless WebP: no pixel loss. The file just gets smaller, usually.
- PNG to JPEG or lossy WebP: some loss, and any transparency is flattened when going to JPEG.
- JPEG to WebP: the JPEG detail is already gone, and a second lossy step can add a little more loss. Use a high quality setting and compare.
- WebP to JPEG: the common route when a client or platform will not accept WebP. See convert WebP to JPG in bulk on Windows.
The safest habit is to keep your originals and write converted copies to a separate folder.
How do I convert a folder of images on Windows?
Windows can re-save images one at a time in Paint, which is fine for a handful of files. For a folder:
- Pick the target format using the table above.
- Decide the size. Converting is a good moment to resize too, since most web images do not need camera resolution.
- Choose a quality level for lossy output. Try two or three settings on a sample.
- Write to a new folder, so the originals stay as they are.
- Spot-check the results, especially text in screenshots and edges in logos.
How does OpticBatch handle format conversion?
OpticBatch is a bulk image resizer and converter for Windows. According to its Microsoft Store listing:
- Converts between JPEG, PNG and WebP natively, in batches of thousands of files.
- Resizes in the same pass using Max Width, Max Height, Percentage Scale or Exact Dimensions, with an aspect-ratio lock.
- Quality slider from 1 to 100 for lossy formats, with a live estimate of the size savings before you run the batch.
- Never overwrites originals. It uses atomic writes, so a cancelled or interrupted batch does not corrupt source files.
- Isolates bad files. A corrupted image gets an error badge and the rest of the batch keeps going.
- Runs locally, with no uploads, no account and no telemetry, in a footprint under 40 MB.
That makes the “test two quality levels, then run the folder” workflow above quick: set the format and quality, read the size estimate, run a sample, then run everything. For more on quality settings, see convert to WebP with quality control, and if you are weighing AVIF too, read AVIF versus WebP.
Set the format and quality, check the size estimate, and run the whole folder.
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What about metadata when converting?
Converting does not automatically remove camera data such as GPS location, and it does not guarantee it is kept either. If you are publishing photos, decide on purpose. For a dedicated privacy pass, MetaForge removes GPS, device serial numbers and other metadata in bulk before you share.
Frequently asked questions
Is WebP better than JPEG?
For website images, usually. Google reports lossy WebP files 25 to 34 percent smaller than comparable JPEGs. For files you send to other people or print, JPEG is still the safer choice because everything opens it.
Is WebP better than PNG?
On the web, often. Lossless WebP keeps every pixel and supports transparency, and Google reports it about 26 percent smaller than PNG on average. Keep PNG when a tool or platform does not accept WebP.
Should I convert all my photos to WebP?
Convert copies for your website. Keep your originals, and keep JPEG versions for anything you share outside the browser.
Does WebP support transparency?
Yes, in both lossless and lossy modes. JPEG does not.
Can I convert JPEG to PNG to improve quality?
No. PNG is lossless, so it preserves what is already in the JPEG, but it cannot restore detail the JPEG discarded. The file will usually get larger.
Try OpticBatch
Get OpticBatch from the Microsoft Store. It is a one-time purchase with no subscription, and the Store listing shows the current price.
Turn a folder of mixed images into the right format for the job, on your own PC.
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Google and WebP are trademarks of Google LLC. Microsoft and Windows are trademarks of the Microsoft group of companies. OpticBatch is not affiliated with or endorsed by Google, Microsoft or Mozilla.
Last updated 20 October 2026. Published by Automata Labs, a software company in Canada.