Which image formats can I convert between?

You can load any format your browser can decode — PNG, JPG/JPEG, WebP, GIF and BMP are the common ones — and export to PNG, JPG or WebP. So you can convert PNG to JPG, JPG to WebP, WebP to PNG, and every other combination of those three targets, all in one place.

Does converting to JPG lose my transparency?

JPG has no alpha channel, so transparent pixels have to be filled with a solid colour. The converter flattens transparency onto the background colour you choose (white by default). If you need to keep transparency, export to PNG or WebP instead, which both support an alpha channel.

What does the quality slider actually do?

For lossy formats (JPG and WebP) the slider sets the encoder quality from 10 percent to 100 percent. Lower values throw away more detail and produce much smaller files; higher values keep more detail at a larger size. The slider is disabled for PNG because PNG is lossless and ignores a quality value.

Will WebP make my files smaller than JPG or PNG?

Usually yes. WebP typically produces files 25 to 35 percent smaller than an equivalent-quality JPG, and far smaller than PNG for photographic content, while still supporting transparency. The summary line shows the exact before-and-after size and percentage saved for your specific images.

Can I convert many images at once?

Yes. Drop or select as many files as you like and they are queued and converted one after another to keep memory use low. Each result has its own download button, and the Download all button packs every converted file into a single zip archive.

Are my images uploaded to a server?

No. Every step — decoding, re-encoding, resizing and zipping — happens locally in your browser using the canvas API. Your images never leave your device, which makes this safe for private photos, screenshots and confidential documents.

Image Format Converter

A single image format converter that handles every direction at once: load PNG, JPG, WebP, GIF or BMP files and re-encode them to PNG, JPG or WebP with a live quality slider, optional resizing, and a one-click zip download. Instead of hunting for a separate “PNG to JPG” or “WebP to PNG” page for each job, you pick the target format here and convert a whole batch in one go — and because it runs entirely in your browser, nothing is ever uploaded.

It is built for the everyday format chores that pile up: shrinking screenshots before attaching them to an email, turning heavy PNG exports into lean WebP for a website, flattening a transparent logo onto white so it works as a JPG, or normalising a folder of mixed-format images into one consistent type. The quality slider, background-flatten colour and resize cap give you real control over the trade-off between file size and visual fidelity.

How it works

When you drop images in, each file is decoded by the browser into an off-screen canvas. The converter then re-encodes that canvas to your chosen format using the built-in canvas.toBlob encoder. For lossy targets (JPG and WebP) the quality slider is passed straight through to the encoder, so a value of 0.6 produces a noticeably smaller file than 0.95. PNG ignores quality because it is lossless.

Because JPG has no alpha channel, any transparent pixels are first painted onto the solid background colour you select — that prevents the ugly black fill some tools leave behind. PNG and WebP keep transparency intact. If you enable resizing, the longest edge is scaled down to your chosen pixel cap (aspect ratio preserved) before encoding, which is the single biggest lever for cutting file size. Files are processed one at a time so a large batch will not exhaust memory, and the Download all button uses an in-browser zip library to bundle every result.

Example

Suppose you export ten UI screenshots as PNG and each is around 1.4 MB. Select WebP, set quality to 80 percent, and drop them in. Each one re-encodes to roughly 180–260 KB — the summary line might read 13.8 MB → 2.1 MB (85% smaller). Need them as JPG for a tool that will not accept WebP? Switch the target to JPG, click Re-apply to all, and the whole queue re-converts in place. Then hit Download all (.zip) to get a single archive named converted-jpg-10.zip. Every byte of that work happened on your own machine.

Notes

This tool targets the three web-standard raster formats every browser can both read and write. Some inputs (such as HEIC from iPhones) cannot be decoded by all browsers; if a file fails it is marked clearly in the queue and the rest continue. For specialised one-way jobs there are dedicated pages too, but for mixed batches and quick back-and-forth conversions this is the fastest route — private, offline-capable, and free.