Images & Media / Image Tools

Image Format Converter

An image format converter changes a picture from one file type to another — JPG, PNG, WebP or AVIF — without the file ever leaving your device. You drop in as many images as you like, pick the target format and a quality level, and the browser re-encodes each one with the Canvas API and bundles them into a ZIP you download. Nothing is uploaded: the pixels are read, transformed and written back inside your tab, so the tool works offline and your files never touch a server.

How to use

1
Add your images
Drag a set of pictures onto the drop zone, or click it to browse. You can select many files at once; JPG, PNG, WebP and AVIF are all accepted and each appears in the list with its size and dimensions.
2
Pick a target format
Choose JPG, PNG, WebP or AVIF. WebP and AVIF are smaller than JPG at the same quality; PNG is lossless. If a browser cannot encode AVIF the button is disabled and a note explains why.
3
Set the quality
For lossy formats drag the quality slider — higher means sharper but larger. The slider is disabled for PNG because PNG ignores quality and keeps every pixel.
4
Convert the batch
Press Convert. Each image is re-encoded in your browser and the list shows its new size and how much smaller it is. Transparent sources headed for JPG are flagged so you are not surprised by the flattening.
5
Download the result
When conversion finishes, download everything as one ZIP, or grab a single file from its row. Because nothing was uploaded, the whole job stays on your machine.

Key facts

WebP efficiencyWebP, developed by Google, typically compresses better than JPEG at the same perceived quality — roughly 25–34% smaller for an equivalent quality level. It also carries an alpha channel, so it can replace both JPG and PNG in many cases.Source:Google WebP documentation
JPEG has no alphaThe JPEG (JFIF) format has no transparency channel. When a source with see-through pixels is encoded as JPG, the transparent areas are composited onto a solid background, which in browsers is black — the transparency is lost.Source:JPEG/JFIF specification
AVIF compressionAVIF (AV1 Image File Format) generally compresses better than both JPEG and WebP, but writing AVIF depends on browser support, so encoding is feature-detected before the option is offered.Source:Alliance for Open Media; caniuse.com
PNG is losslessPNG stores pixels without lossy compression, so converting into PNG preserves the image exactly and a quality setting has no effect. It is the right target when you must keep transparency or perfect detail.Source:Portable Network Graphics (PNG) specification, W3C
Conversion stays on the deviceThe re-encoding uses the HTML Canvas API and the File API, which run entirely in the page. The image bytes are never transmitted to a server, so the conversion works offline and the files do not leave the machine.Source:HTML Canvas / File API

Frequently asked questions

Are my images uploaded to a server?

No. Every step runs in your browser using the Canvas API and the File API. The image bytes are read from your disk, re-encoded in the tab, and written into the download — they are never sent to a server, and the tool keeps working with no internet connection. That is also why there is no file-size limit set by us beyond what your browser can hold in memory; very large images are scaled down to keep the conversion stable.

Which formats are supported?

You can convert between JPG, PNG, WebP and AVIF. JPG and PNG are supported everywhere; WebP works in every current browser; AVIF encoding depends on the browser, so if a browser cannot write AVIF the option is disabled and a note tells you to pick another format. The source can be any of the four, and the same four are the targets.

Does converting lose quality?

It depends on the target. PNG is lossless, so converting to PNG keeps every pixel exactly and the quality slider does nothing. JPG, WebP and AVIF are lossy: a lower quality number makes a smaller file but softens detail. For photos a quality around 80–92 is usually indistinguishable from the original while still shrinking the file a lot; raise it toward 100 when you need the sharpest result and do not mind a bigger download.

Why do transparent PNGs look wrong after converting to JPG?

Because JPG has no transparency. When a PNG with see-through areas is saved as JPG, the transparent pixels are flattened onto a solid background — in browsers that background is black. If you need to keep transparency, convert to PNG or WebP instead of JPG. The tool warns you about this before you convert whenever it detects a transparent source.

How do I get all the converted files at once?

After the batch finishes, use the Download ZIP button. It packages every successfully converted image into one archive named after the target format — for example converted-webp.zip — so a folder of pictures becomes a single download instead of dozens of separate clicks. Individual files can also be downloaded one at a time from their row.

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