PNG and MNG tools
Browser gamma test

PNG Web Site

 html  html  html  html
 none  none  none  none
  * The GIFs on this page are LZW-free


If the table shows only four large rectangles, one light gray, two medium gray, and one dark gray, your browser is not processing the PNG gAMA chunk. If each is subdivided into several different patches, then your browser is processing the gAMA chunk. The one that matches the "none" strip at the right edge of each rectangle is the one whose reciprocal best matches the display gamma assumed by your browser (some browsers will do gamma compensation even with PNGs that have no gamma chunk; if this is the case, the GIF and JPEG will not match the "none" patch, and the GIF and JPEG are more likely to be displayed in the assumed display gamma).

The "sRGB" and "html" patches should look the same, and they should both closely resemble the "1/2.2" patch.

The small "none" patch, the GIF and JPEG below it, and the "file gamma=none" strip at the right have the nonstandard ICCPROFILE="none" attribute, which will be ignored by some browsers (which is OK). The rest of the patches do not have this attribute.

Hit "reload" if not all of the patches are present. Some browsers will time out before downloading them all because there are so many.

Results with various browsers and platforms are here (or will be someday).

© 2000, Glenn Randers-Pehrson glennrp at