Which graphic file formats are supported by browsers?

JPEG, GIF and PNG can be displayed with the img tag and will work in all browsers, the object element can be use for displaying images specifying its MIME type, but what other graphic formats are supported by img or object tag in most browsers without installing plugins? (TIF, SVG, PCX, PICT, etc..)

There's an excellent chart on wikipedia that lists common image types and their support by browser.

The file types you listed (jpg, gif and png) seem to be the main formats supported by nearly every browser, albeit with certain caveats:

Internet Explorer supports PNG images but is unable to correctly display images with gamma correction or color correction. Versions of Internet Explorer prior to version 7 are unable to correctly display images with alpha channel (for transparency) without additional coding

BMP will work most anywhere.

But for web work, you should probably stick to the three you listed in your question.