PNG vs JPG vs WebP vs BMP vs GIF — Which Format to Use

Choosing an image format comes down to three questions. Does the image need transparency? Is it a photograph, or a graphic with flat colours and sharp edges? And will the destination accept a modern format? Here's how each format answers them, and what to expect when you convert one into another.

The five formats at a glance

PNG: exact pixels, larger files

PNG stores every pixel exactly. Screenshots stay crisp, text stays sharp, and a logo's transparent background stays transparent. The cost is size on photographs, where the fine noise that JPG throws away has to be stored faithfully. A phone photo saved as PNG is often several times the size of the same photo as a good-quality JPG. Use PNG when every pixel matters. Don't use it for a photo gallery.

JPG: small photos, soft edges

JPG discards detail your eye is least likely to notice, and the quality setting controls how much. At high settings the loss is invisible on photographs. On sharp edges, though, JPG leaves "ringing" artifacts: faint halos around text, UI lines, and flat-colour shapes. JPG has no transparency at all.

WebP: usually the smallest of the modern choices

WebP supports lossy compression like JPG, and transparency like PNG, in one format. Google's WebP documentation puts lossy WebP at 25–34% smaller than JPEG at equivalent SSIM quality, and lossless WebP at 26% smaller than PNG. Every current major browser supports it. The main reasons to still convert away from WebP are older desktop software, some email clients, and upload forms that only accept JPG or PNG.

BMP: no compression at all

BMP stores raw pixel values. The converter on this site writes 24-bit BMP, 3 bytes per pixel, with each row padded to a multiple of 4 bytes. For a 1920 × 1080 image, that's 1920 × 3 = 5,760 bytes per row, × 1,080 rows, plus a 54-byte header: 6,220,854 bytes, about 6.2 MB, whatever the image contains. The same picture as a JPG is usually a few hundred kilobytes. Only use BMP when a piece of software specifically requires it.

GIF: 256 colours, animation

GIF can show at most 256 colours in a frame. The converter maps every pixel to a fixed 256-colour palette: 8 levels of red, 8 of green, and 4 of blue. That's fast and predictable, but smooth gradients in a photo turn into visible bands. GIF's transparency is also all-or-nothing, with no soft edges. Its one remaining strength is simple animation, and even there, converting an image in the browser only reads the first frame of an animated GIF.

What changes when you convert in the browser

The Image Format Converter draws your image onto a canvas and re-encodes it in the target format. That's why nothing is uploaded, and it has a few consequences worth knowing:

• Transparency to JPG, BMP or GIF becomes white. These formats have no smooth alpha channel, so transparent areas are filled with white. (Without that step they'd come out black.) Convert a transparent logo to PNG or WebP to keep it transparent.
• Metadata is removed. Camera EXIF data, including GPS location, isn't copied into the new file. The browser applies the photo's rotation first, so a portrait phone photo stays upright.
• Colour profiles aren't carried over. Output is standard sRGB. Photos from phones that shoot in a wider colour space can look very slightly less saturated.
• Quality applies to JPG and WebP only. The converter's default is 90%. PNG, BMP and GIF have no quality setting.
• Converting never adds quality back. A compressed JPG turned into PNG keeps its artifacts, now stored losslessly in a bigger file.

Choosing, in practice

• Logo or icon with a transparent background: PNG, or WebP for the web.
• Photo for a website: WebP, or JPG where WebP isn't accepted.
• Screenshot with text: PNG. JPG blurs the text edges.
• A form insists on JPG: convert, knowing any transparency turns white.
• Legacy tool demands BMP: convert, and keep the original, because the BMP will be large.

If the file is too large after choosing the right format, the next step is usually reducing its pixel dimensions with the Image Resizer. Its aspect-ratio lock stops the image from being stretched. Then adjust quality with the Image Compressor. The compression guide explains why resizing first usually saves far more than lowering quality.