“8-bit” means two unrelated things depending on who’s talking. To a computer engineer it describes a processor that handles 8 bits of data at a time, which is why the NES and the Commodore 64 are called 8-bit machines. To anyone working with images it describes color depth, where 8-bit color means 256 colors. To everyone else it’s a look: chunky pixels and beepy music. Those three meanings don’t line up, which is the source of most of the confusion.
Meaning 1: the processor #
In computer architecture, 8-bit refers to the width of the data a processor works with. As Wikipedia’s article on 8-bit computing puts it, “8-bit integers or other data units are those that are 8 bits wide (1 octet).” That width applies to the CPU’s registers and to the data bus that moves information around.
Eight bits gives 256 possible values (2 to the power of 8). Read as unsigned numbers that’s 0 to 255; as signed two’s complement numbers it’s -128 to 127.
Most 8-bit CPUs paired that with a 16-bit address bus, giving a direct address space of 64 KB. That was the practical compromise between component cost and usable memory at the time.
The famous chips were the MOS Technology 6502, the Zilog Z80 and the Intel 8080. The machines built on them include the Apple II, the Commodore 64, the BBC Micro, the Atari 8-bit computers, the Atari 2600 and the Nintendo Entertainment System.
Meaning 2: color depth #
In imaging, bit depth describes how many bits describe each pixel’s color, and this is where it gets slippery, because “8-bit color” and “8 bits per channel” mean very different things.
8-bit color means 256 colors total, “usually from a fully-programmable palette,” according to Wikipedia’s article on color depth. Each pixel stores a number that indexes into a color table rather than storing red, green and blue values directly. That’s called indexed or palettized color, and it was memory-efficient: one byte per pixel instead of three.
8 bits per channel is a different thing entirely. Wikipedia notes that “24 bits almost always use 8 bits each of R, G, and B (8 bpc),” which produces 16,777,216 colors. This is ordinary truecolor, what your phone camera produces and your screen displays. Photo editors call it 8-bit, and it has nothing to do with retro graphics.
So a modern JPEG is “8-bit” in the per-channel sense while having millions of colors. An old GIF is “8-bit” in the indexed sense with at most 256.
Why 8-bit consoles didn’t show 256 colors #
The 8-bit label on a console refers to its CPU, not its graphics, and the graphics were usually far more limited.
The NES had an 8-bit CPU and a fixed palette of a few dozen colors, of which only a small number could appear on screen at once, arranged in background and sprite palettes with strict per-tile rules. How many colors the NES could display covers those limits, including why sprites got three colors plus transparency.
The original Game Boy went further in the other direction, storing two bits per pixel for four shades of gray-green. Game Boy palette hex codes has the values people use to imitate it.
Meanwhile a PC running 8-bit indexed color in the early 1990s could show 256 colors at once, more than any 8-bit console, on a 16-bit or 32-bit processor. The labels simply describe different parts of the machine. Why old games had limited colors explains what was actually driving the restrictions, which was memory cost and video hardware rather than the CPU’s bit width.
Meaning 3: the art style #
Loosely, “8-bit” has become a name for retro pixel art and chiptune music. It’s imprecise, and it’s now the most common way the term is used.
Two things worth knowing when you use it that way:
- Much of what people call 8-bit graphics is actually from 16-bit machines like the Super Nintendo and Sega Mega Drive, which had far larger palettes and more detailed sprites.
- A lot of modern pixel art follows no hardware limits at all and simply borrows the look.
None of that makes the casual usage wrong, and it does explain why a search for “8-bit” turns up everything from NES sprites to full-color modern illustrations. What pixel art is draws the lines more carefully.
What this means when you’re making pixel art #
Two practical takeaways.
Pick a palette, not a bit depth. “Make it 8-bit” isn’t a setting. What produces the look is a specific small palette plus a coarse grid. Four Game Boy greens read as far more retro than 256 well-chosen colors.
Save in a format that keeps hard edges. PNG preserves indexed color and sharp pixel boundaries. JPEG, designed for photographs, smears them.
In Pixelize that maps to two controls: a pixel size on the Pixel tab for the grid, and one of 25 hex-accurate palettes on the Color tab for the colors, including the NES, the Game Boy, PICO-8, the Commodore 64, CGA, Apple II and ZX Spectrum. Exports are PNG. 8-bit photo filter covers what separates a convincing retro conversion from a plain blur.
Frequently asked questions #
How many colors is 8-bit? #
In color depth terms, 256, usually chosen from a programmable palette. If someone means 8 bits per channel instead, that’s 24-bit truecolor with 16,777,216 colors. The two get called 8-bit interchangeably, so ask which one is meant.
Was the NES 8-bit? #
Yes, in the processor sense. Its CPU was based on the 6502 family and handled 8 bits at a time. Its graphics were far more restricted than 256 colors, with a fixed hardware palette and strict rules about how many colors each tile and sprite could use.
Is 16-bit twice as good as 8-bit? #
Not twice as good, and not directly comparable. A 16-bit CPU processes wider chunks of data and addresses more memory, which in practice meant bigger sprites, more colors on screen and better sound. The difference people notice in games came from the graphics and audio hardware alongside the CPU.
What does 8-bit mean in Photoshop? #
Bits per channel. An 8-bit image there has 8 bits each for red, green and blue, which is standard truecolor. Switching to 16-bit per channel gives smoother gradients for heavy editing, and has nothing to do with retro graphics.
How do I make an 8-bit style image? #
Convert a photo onto a coarse grid, map it to a small palette from an era you like, dither the gradients, and export as PNG enlarged with nearest-neighbor scaling. How to turn a photo into pixel art walks through it on both phone and desktop.