Free Image Converter
Convert PNG, JPG and WebP images in your browser — no upload, works offline, no sign-up and no watermarks. Your photos never leave your device.
Runs entirely in your browser — your images are never uploaded.
- No upload Images are processed on your device and never leave it.
- Works offline After the first visit it runs with no internet connection.
- No size limits No file caps or paywalls — only your device memory.
- Private by design Nothing to sign up for and nothing sent to a server.
How it works
When you pick a file, the image is decoded into memory and re-encoded to the format you
choose. JPEG output is produced by the MozJPEG encoder, which yields
smaller files than the browser at the same quality, and PNG output is run through
OxiPNG for a lossless size reduction that keeps transparency intact;
both are compiled to WebAssembly and load only when first needed. If a codec cannot
load, the converter falls back to the browser's built-in canvas.toBlob()
encoder. Because all of this runs in JavaScript on your own computer, there is no server
round trip — your originals are never transmitted anywhere.
How to convert an image
- Click the drop zone above and select one or more images, or drag files onto it.
- Choose your output format: PNG, JPEG or WebP.
- For JPEG and WebP, drag the quality slider to balance file size against sharpness.
- Press Convert images and wait a moment for processing to finish.
- Review the before/after file sizes, then click Download on each result.
Local vs cloud image tools
Most online converters quietly upload your files to a remote server, queue them, and email you a link. That is slow, leaks your private images to a third party, and often comes with size caps or paid tiers. This tool flips that model: the conversion engine ships to your browser, so the work is private and there is no upload or queue. There is nothing to install, no account to create, and no watermark on the output. Processing speed depends on your device rather than a connection — quick for everyday photos, though a very large image or big batch can be slower on older hardware.
| Local (this site) | Typical cloud tool | |
|---|---|---|
| Upload required | No | Usually |
| File-size caps | None (device memory) | Common |
| Works offline | Yes, after first load | No |
| Images stay private | Yes — never sent | Sent to a server |
Switching formats is one of the simplest ways to shrink a web page or free up storage. Re-encoding a heavy PNG screenshot as WebP can cut its size by half or more with no visible difference, while converting a transparent graphic to PNG preserves crisp edges. Photographers exporting for the web often choose JPEG at around 80% quality for the best trade-off between clarity and weight.
All image tools
Image guides
New to image formats and size limits? Our guides explain how to compress to an exact file size, how to choose between PNG, JPG and WebP, and how to prepare a photo for online forms.
Frequently asked questions
Do my images get uploaded?
No. Every conversion is processed locally in your browser, so your files never leave your device. JPEG output uses the MozJPEG encoder and PNG output is optimised with OxiPNG, both compiled to WebAssembly, with the Canvas API as a fallback. That keeps private photos private and means there is no upload step to wait for.
Does it work on slow or metered internet?
Yes. Nothing is uploaded or downloaded while you convert, so your connection speed does not affect the work at all. Only the small app itself loads once over the network; after that it is cached and ready.
Does it work offline?
Yes, after the first visit. The site is a Progressive Web App, so once it has loaded the converter keeps working with no internet connection. The only exceptions are the optional codecs that download the first time you use them — the HEIC decoder, and the MozJPEG and OxiPNG encoders — after which they are cached for offline use too.
Is there a file size limit?
There is no fixed limit imposed by the tool. The practical ceiling is your device memory, so a very large image or a big batch can be slow or run out of memory on an older phone, while normal photos convert quickly.
Which image formats can I convert between?
You can load any format your browser can decode (including PNG, JPG, WebP, GIF and BMP) and export to PNG, JPEG or WebP. WebP usually gives the smallest files at the same visual quality.
When should I use PNG vs JPEG vs WebP?
Use PNG for graphics, logos and screenshots that need sharp edges or transparency. Use JPEG for photographs where small size matters. WebP is a modern format that often beats both, with smaller files and optional transparency.
Why did my JPEG file get a white background?
JPEG does not support transparency. When you convert a transparent PNG or WebP to JPEG, the see-through areas are filled with white so the photo displays correctly. Export to PNG or WebP if you need to keep transparency.
Is there a limit on file size or how many images I can convert?
There is no artificial limit. Because processing happens on your own machine, the practical ceiling is your device memory. You can convert several images at once and download each result individually.
Does this work on phones and tablets?
Yes. The converter runs in any modern mobile or desktop browser. On iPhone you can even convert the HEIC photos your camera produces using the dedicated HEIC to JPG tool.
All processing happens on Image Tools entirely within your browser. Images are never uploaded to a server.