Errorlevelanalysis.com is an online tool for cheching a photograph if it was digitally manipulated in Photoshop or other editor.

You provide a link to the image that is hosted somewhere else and it will show differing error levels throughout your image. Error level analysis can help you work out if a photo has been digitally altered. Photos in a jpeg file format actually lose quality each time they are resaved.

If a picture has been resaved many times, or if a picture is of a very low jpeg quality, it is quite difficult to determine accurately whether it has been digitally altered. Likewise, if all parts of a picture have been saved the same amount of times, it will not pick up either. This tool is set up to work on high quality jpeg photos (95% quality), and as such, if it is run against lower quality photos, the results can be harder to interpret.

Who: Those curious if a particular photo has been edited.

Cost: Free

Registraion: Not required

Website: errorlevelanalysis.com