Start from what you want to do. Each answer says what to expect, including where a tool stops.
Make an image file smaller
There are two ways, and resizing usually beats squeezing. Our 3000 × 2000 test photo was 990 KB. Compress Image at quality 75 made it 569 KB; forcing it under 50 KB needed quality 11, which leaves visible blocks. Resizing it to 1280 pixels wide at the same quality 75 gave 90 KB that still looked clean.
So for a web page or an email, set a maximum width first (1200 to 1600 pixels is plenty for most screens), then compress. For a form that wants a photo under 50 KB, choose the target in Compress Image and it finds the highest quality that fits. Compress Image also turns PNGs into WebP, which keeps transparency at about half the size; Safari cannot save WebP, so there it makes a JPG without transparency.
Change an image to another format
The Raster to Raster converter handles JPG, PNG, WebP, GIF, BMP and TIFF on our server. Phone photos are turned upright, the color profile is kept where the new format can use it, and camera and location details are left out. JPGs are saved at quality 90.
Transparency survives in PNG, WebP, TIFF and GIF; JPG and BMP have none, so clear areas turn white. Animated GIFs and WebPs stay animated when the output is GIF or WebP, with the same frames and timing; any other output keeps the first frame.
Turn a picture into a vector (SVG, EPS, DXF)
Tracing finds the dark shapes in an image and redraws them as paths, so the result scales to any size. It produces one color: everything darker than mid-gray becomes a black shape, everything lighter disappears. That suits logos, signatures, stamps and line drawings. A photo comes out as blotches.
Use a clean, high-contrast original, as large as you have. Transparent areas are filled with white before tracing, and an animated GIF gives its first frame. Already have a vector? Vector to Vector converts SVG, EPS and DXF without tracing, and Vector to Raster turns them into images.
Get the right size or shape
Resize Image sets exact pixel dimensions (up to 4000 per side), offers social and common presets, and can aim for a file size in KB. Crop Image cuts away what you do not need, freely or at 1:1, 4:5, 16:9 or 9:16. Both save JPGs, so transparent areas turn white.
A print shop asking for 300 DPI usually means enough pixels for the print size. The Image DPI Converter can write the DPI number into a PNG or JPG without changing a pixel, or resample to it; the number on its own does not make a photo sharper.
Cut out a person or product
Remove Background uploads the image to our server, where an open-source AI model (U²-Net) picks out the subject. In our tests it took 1.6 to 3.3 seconds. A product on a plain background and a logo came out clean; hair and fur get soft, partly see-through edges, so check them at full size before you use the cut-out on a very different background.
Make passport or ID photos
Passport Photo Maker finds the face, crops the photo around it and lays out the copies on an A4 sheet to print at home or in a shop; up to 15 fit at 2×2 in. It makes the 2×2 in (51×51 mm) size used in the United States, a 1×1 in stamp size and standard print sizes. It does not yet make 35×45 mm, used in the UK, Schengen countries and India, and it does not change the background, so start from a photo against a plain, light wall.
Touch up, combine or embed images
Edit Image adjusts brightness, contrast, saturation, blur and sharpness and rotates without cropping the corners, then downloads at full resolution. Merge Images joins pictures side by side or stacked into one PNG, handy for before-and-after comparisons. The Base64 encoder turns text or a small file into Base64 text, and decodes Base64 back into readable text.