TL;DR: To convert an image format online, load the file in a browser-based converter, pick the target format, and download. Choose PNG for transparency, JPG or WebP for photos, and ICO for favicons. A client-side converter such as the free Image Format Converter does the work on your device, so the file never leaves your computer.
Converting an image file format is a small task with more traps than most guides mention. This one covers which format fits which job, what conversion does to quality, and how to confirm your file was never uploaded.
Which image format should you use?
Pick the format by what the image is for, not by what format the file arrived as.
- PNG when you need a transparent background, sharp text, or a lossless file. Logos, screenshots, and UI mockups belong in PNG.
- JPG for photos and anything with smooth gradients. It has no transparency, so a JPG always fills the frame.
- WebP for images that live on a website. Google's tests show WebP is 25 to 34 percent smaller than JPG at the same visual quality, and about 97 percent of browsers support it. See Google's WebP documentation.
- ICO for the small favicon icon in the browser tab.
- GIF only when you need an animated image and WebP cannot replace it.
BMP is mostly a legacy format. Its one trait is that it is completely uncompressed, which is why BMP files are several times larger than the other formats.
How do you convert an image format online?
The free Image Format Converter on EasyToolsBox runs the conversion in three steps:
- Open the page and drop in an image. PNG, JPG, WebP, GIF, BMP, and ICO are all accepted.
- Pick the target format, and set a quality value when the output format supports one.
- Download the converted file. The page shows the original and converted file sizes side by side.
Batch conversion works the same way: select several files, choose one output format, and every file comes back converted.
Does converting an image format lose quality?
Changing the file format does not degrade the image, with one caveat. When the source is a lossy format such as JPG, the damage happened when the JPG was first saved. Converting that JPG to PNG keeps it lossless from now on, but it does not restore the detail JPG already discarded. JPG to PNG conversion preserves current quality; it cannot recover what was lost earlier.
Two format quirks catch most people:
- JPG has no transparency. Converting an image with transparent areas from PNG to JPG turns those areas solid white.
- GIF animation does not survive conversion. Converting an animated GIF to PNG, JPG, or WebP keeps only the first frame.
For lossy output formats such as JPG and WebP, the quality slider sets the balance between file size and sharpness. Quality 80 to 85 looks identical to 100 for most photos at roughly half the file size.
What is the best image format for the web in 2026?
WebP is the default. It offers the lossless option of PNG with smaller files than JPG, and Chrome, Firefox, Edge, and Safari have supported it since Safari 14.1. When a system still rejects WebP, JPG is the compatibility fallback.
Should you convert or resize first?
Convert to the final format first, then resize to the final dimensions in a second step. That produces one clean export instead of two lossy passes and keeps the quality setting in one place. The guide to resizing without losing quality lists the exact pixel sizes and quality settings.
What mistakes do people make when converting formats?
- Converting PNG to JPG for email and losing the transparency. Email clients do not require JPG. A PNG attaches fine and keeps the transparent background.
- Saving a logo as JPG. JPG has no transparency and its compression softens hard edges. Logos stay sharp only in PNG.
- Re-converting the same file over and over. Every lossy save adds a little more loss. Convert once from the original and stop.
- Choosing a BMP when a WebP will do. BMP files are far larger with no visible benefit on a screen.
FAQ
Is it safe to convert images online?
It depends on where the conversion runs. Browser-based converters such as the EasyToolsBox Image Format Converter process the image on your device with the Canvas API, so nothing is uploaded. Verify it yourself: load the page, disconnect from the internet, and convert an image. It still works.
Does converting JPG to PNG improve quality?
No. PNG stores the image losslessly, so the conversion adds no new loss, but it cannot repair the compression artifacts already baked into the JPG. If the original JPG is blurry or blocky, the PNG will be too.
Can I make a favicon with an online converter?
Yes. Convert your image to ICO, the favicon format browsers use. Start with a square image, 256 by 256 pixels or larger, so the browser can scale it down cleanly.
What image formats are supported?
PNG, JPEG, WebP, GIF, BMP, and ICO, convertible from any one to any other. Files up to 50MB are accepted.
Does format conversion work on mobile?
Yes. Client-side converters run in any browser, so the same page works on a phone or tablet. On Android, long-press the download link to save the image; on iOS, tap it.