The two most common image formats on the web serve completely different purposes. Choosing the wrong one means either bloated file sizes or unnecessary quality loss.
JPG — Best for photographs
JPEG uses lossy compression that discards colour detail the eye barely notices. A typical 5MB phone photo compresses to 400KB at 80% quality with no visible difference. JPG is the right choice for: photographs, social media images, product shots, and any image with complex colour gradients.
PNG — Best for graphics
PNG uses lossless compression — every pixel is stored exactly. It also supports transparency (alpha channel). PNG is the right choice for: logos, icons, screenshots, illustrations, text-heavy images, and anything requiring transparency.
Quick decision guide
Is it a photo? → JPG. Does it have text or sharp edges? → PNG. Does it need a transparent background? → PNG. Are you uploading to a website and file size matters? → JPG or WebP.
Why browser-based tools are better for privacy
Traditional online tools upload your files to a remote server, process them there, and send the result back. This means your files — which may contain sensitive personal, financial, or confidential information — pass through and are temporarily stored on a computer you do not control. Browser-based tools like the ones covered here work entirely on your own device. Your files never travel across the internet, which eliminates the privacy risk completely.
What to look for in a free online tool
When choosing a free tool, check three things. First, does it upload your files or process them locally? Local processing is always more private. Second, does it add watermarks or impose daily limits? Genuinely free tools do not. Third, does it require an account? The best tools let you start immediately without signing up. A tool that processes files in your browser, adds no watermarks, and needs no account gives you the most freedom and privacy.
Tips for the best results
For the highest quality output, always start with the highest quality source file you have. Avoid repeatedly processing the same file through multiple tools, as each step can compound small quality losses. When a tool offers quality or compression settings, experiment with them to find the right balance between file size and visual quality for your specific needs. And always keep a backup of your original file before making changes.