Batch Image Converter
Batch-convert photos between JPEG, PNG and WebP, with a quality control for the lossy formats and a heads-up before a transparent PNG becomes a JPEG. If you like, flatten transparency onto a background colour first. None of it leaves your device.
- 100% free
- Private & safe
- Runs in your browser
Your files are processed securely in your browser and are not uploaded to our servers.
Popular image conversions
Why use Convert Image?
Convert Image lets you edit and optimise images in seconds, right in your browser — no bulky software to install and nothing uploaded to a server.
- 100% private: files are processed in your browser and never uploaded.
- Completely free, with no account, no watermarks and no usage limits.
- JPEG ⇄ PNG ⇄ WebP
- Add one or more images in any supported format.
- Works on any device — desktop, tablet and phone — and is fully keyboard accessible.
What it can do — and its limits
- Converts between JPG, PNG and WebP with a quality control for lossy output.
- Flattens transparency onto a background colour when converting to JPG.
- Converts several images in a batch; everything runs in your browser.
How to use Convert Image
- Add one or more images in any supported format.
- Pick the target format: JPEG, PNG or WebP.
- For lossy targets, set the quality. If a PNG has transparency and you convert to JPEG, choose a background colour to flatten onto.
- Convert and download each file, or all of them as a ZIP.
Examples
- Converting a folder of PNG screenshots to smaller WebP files.
- Turning a WebP download into a widely compatible JPEG.
Worked example
Input
A PNG logo with a transparent background, converted to JPG.
Output
A JPG with the transparent areas flattened onto white (or a colour you choose).
Supported formats & limits
- JPEG ⇄ PNG ⇄ WebP
Convert to…
| Goal | Convert to |
|---|---|
| Smallest photo for the web | WebP (or JPG) |
| Keep transparency / sharp edges | PNG or lossless WebP |
| Maximum compatibility | JPG (photos) or PNG (graphics) |
Limitations
- JPEG does not support transparency, so PNG transparency must be flattened onto a colour.
- Browser support for encoding WebP is very good but not universal on older browsers.
Common problems & fixes
Transparency turned black or white.
JPG has no alpha channel — keep PNG/WebP, or pick a flatten colour when converting to JPG.
Converted file is larger than the original.
Converting a photo to PNG inflates it. For photos choose JPG or WebP instead.
Sources & references
Last verified August 2026.
Frequently asked questions
What happens to transparency when I convert PNG to JPEG?
JPEG cannot store transparency, so transparent areas are filled with the background colour you choose before conversion.
Can I convert several images at once?
Yes, batch conversion is supported and you can download the results as a single ZIP.
Will converting change the image quality?
Converting to JPEG or WebP applies lossy compression; converting to PNG is lossless but produces larger files.