Image converter
Change image formats in a batch: PNG to JPG for smaller photos, JPG to PNG for editing, or WebP to something every app opens. Resize by percentage or pixels at the same time. Nothing is uploaded.
About the image converter
Change image formats in a batch: PNG to JPG for smaller photos, JPG to PNG for editing, or WebP to something every app opens. Resize by percentage or pixels at the same time. Nothing is uploaded.
Part of SmartCalcy’s files, images & design tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the image converter
What it calculates and when to use it
Converts images between JPG, PNG and WebP (and AVIF where your browser supports it) and resizes them at the same time, in a batch, without uploading anything.
How to use it, step by step
- Drop images on the page or choose them.
- Choose the format to convert to.
- Optionally resize by percentage or to a pixel size.
- Download each image or all of them as a ZIP.
What each input means
- Convert to – JPG, PNG, WebP, or AVIF if supported.
- Quality – For JPG, WebP and AVIF. Starts at 90%.
- Background – Fills transparent areas when saving as JPG.
- Resize – Keep size, by percentage, or to a width and/or height in pixels.
How to read the results
- Converted – Number of images converted and a preview of each with its new size.
The formula
Each image is drawn onto a canvas at the new size and saved in the chosen format. If only a width or height is given, the other side keeps the original proportions.
A worked example
A 1,200 × 800 PNG screenshot converted to WebP at 90% is usually a fraction of its original size, while JPG would fill any transparent areas with the background colour.
Assumptions and limits
- Animated GIFs are converted using their first frame.
- HEIC photos can only be converted if your browser can open them.
Common mistakes
- Converting a JPG to PNG to “improve quality”: it only makes the file bigger.
- Forgetting that JPG has no transparency.
Frequently asked questions
Which format is smallest?
Usually WebP or AVIF for photos, then JPG. PNG is best for sharp graphics and transparency.
Can I convert many images at once?
Yes, add as many as you like and download them as a ZIP.
Are my images uploaded?
No. Conversion happens on your device.