How color depth is counted
Each channel stores a number of bits, and those channels multiply together. Eight bits per channel for red, green, and blue gives 24-bit color, with 256 steps in each channel and about 16.7 million possible colors.
An alpha channel is usually counted separately, which is why a file with transparency is often described as 32-bit even though color itself still uses 24.
What deeper depth buys
More steps per channel produce smoother transitions. In skies, shadows, and studio backdrops, insufficient depth causes banding, where a smooth gradient breaks into visible stripes. High-bit files also absorb repeated exports with fewer visible shifts in tone.
Editing benefits too. Adjusting exposure or color repeatedly rounds values, and files with generous depth absorb more of those operations before artifacts show.
- 8-bit per channel: standard for web and photography
- 16-bit per channel: used for editing and TIFF masters
- Grayscale: one channel, typically 256 gray levels
- Extra alpha channel: opacity instead of color
Color depth and file size
Depth adds data in proportion to bits per pixel, so deeper files weigh more before compression. Web formats standardize on 8-bit channels because displays rarely show the difference.
Filekind handles standard 8-bit web images through its JPEG, PNG, and static WebP conversions, which is what typical phone and camera output already uses. That matches what browsers and upload forms expect, so files stay compatible from processing to delivery.