Anti-aliasing is a rendering technique that smooths jagged edges and reduces shimmering in a rendered image by estimating how much of each pixel a shape actually covers and blending colors along edges accordingly. Among graphics settings in games, it is one of the oldest and most visible options, and it trades image stability and clarity against GPU cost and, with some methods, softness.
The problem it solves is called aliasing: a screen samples a continuous scene at a fixed grid of pixels, so diagonal and curved lines turn into stair steps, often called jaggies, and fine detail such as wires, foliage or distant fences flickers as the camera moves. Anti-aliasing methods differ in where they add information, how expensive they are and what side effects they introduce.
Why aliasing appears in rendered images
A GPU decides the color of each pixel by testing a sample point, usually the pixel center, against the scene’s triangles. When an edge passes through a pixel, that single sample is either inside or outside the triangle, so the pixel becomes fully one color or fully another. The result is geometric aliasing, the classic stair-step edge.
Other forms are just as common in modern games. Shading aliasing comes from high-frequency lighting such as sharp specular highlights, texture aliasing from detailed textures viewed at a distance, and temporal aliasing from detail that shifts between pixels from frame to frame, producing crawling and flicker. Effective anti-aliasing must address all of them, which is why older edge-only methods fall short in current engines.
Main anti-aliasing methods
Anti-aliasing methods fall into three families. Supersampling renders more samples per pixel for everything. Multisampling adds samples only for geometric coverage. Post-process and temporal methods work on the finished image, optionally reusing information from previous frames. The table compares the methods most often found in game menus.
| Method | How it works | Relative cost | Typical side effect |
|---|---|---|---|
| SSAA | Renders at a higher resolution and downscales | Very high, up to 4x pixels | Excellent quality, heavy load |
| MSAA | Extra coverage samples on triangle edges | Moderate to high | Misses shading and transparency aliasing |
| FXAA | Detects edges in the final image and blurs them | Very low | Softens textures and text |
| SMAA | Pattern-based edge detection, optional temporal mode | Low | Less blur than FXAA, weaker on motion |
| TAA | Accumulates jittered samples across frames | Low to moderate | Ghosting and softness in motion |
Temporal anti-aliasing (TAA) became the default in most modern engines because it handles every kind of aliasing at a low cost. It shifts the camera by a sub-pixel jitter each frame and blends the current frame with a reprojected history using motion vectors. When the history is rejected incorrectly or kept too long, the result is ghosting trails behind moving objects or a smeared image.
Anti-aliasing and upscalers
Modern upscalers are built on the same principle as TAA. DLSS, FSR and XeSS accumulate jittered samples over time to reconstruct an image, and they double as anti-aliasing solutions. Most of them offer a native-resolution mode, such as DLAA or FSR Native AA, that uses the reconstruction for anti-aliasing without lowering the internal resolution.
Because of this overlap, games often disable or hide the separate anti-aliasing option when an upscaler is active. Machine-learning reconstruction usually preserves fine detail better than classic TAA and reduces ghosting, but it can introduce its own artifacts such as disocclusion shimmer around fast-moving edges. Render scale interacts with all of these methods: rendering above 100% is effectively supersampling.
| Setting | Main goal | Relationship to anti-aliasing |
|---|---|---|
| Upscaler (DLSS, FSR, XeSS) | Higher frame rate from lower resolution | Includes temporal anti-aliasing |
| Render scale | Change internal resolution | Above 100% acts as supersampling |
| Anisotropic filtering | Sharp textures at oblique angles | Reduces blur, not edge aliasing |
| Sharpening filter | Restore perceived detail | Often paired with TAA to offset softness |
Choosing an anti-aliasing setting
The right choice depends on resolution, pixel density, performance headroom and personal tolerance for blur. At 4K on a typical monitor size, aliasing is less visible, so a light method may suffice. At 1080p, aliasing is pronounced and temporal methods give the most stable image, at the price of some softness.
| Situation | Recommended choice | Reason |
|---|---|---|
| Modern game with an ML upscaler | DLAA or native AA mode | Best stability and detail |
| Modern game without an upscaler | TAA plus mild sharpening | Handles all aliasing types |
| Older forward-rendered game | MSAA 4x | Clean edges at acceptable cost |
| Weak GPU or handheld | SMAA or FXAA | Minimal performance impact |
| Large GPU headroom, older title | Supersampling or high render scale | Highest image quality |
MSAA is often unavailable in modern titles because they use deferred rendering, where lighting is calculated from screen-space buffers and multisampling becomes expensive and incomplete. Disabling anti-aliasing entirely is rarely advisable in such games, because many effects, including hair, foliage and reflections, are designed to be resolved by TAA and look broken without it.
Common misconceptions about anti-aliasing
- Higher resolution removes the need for anti-aliasing. It reduces visible jaggies but not temporal flicker on fine detail.
- FXAA and TAA are interchangeable. FXAA works on a single frame; TAA uses history and fixes motion shimmer.
- Sharpening adds real detail. It only increases local contrast and can amplify noise.
- More MSAA samples always help. Beyond 4x, gains are small and shading aliasing remains.
Another misunderstanding concerns input lag. Anti-aliasing itself adds negligible latency; any responsiveness loss comes from the lower frame rate caused by its GPU cost, which is most noticeable with supersampling.
A non-technical view
A screen is made of tiny squares, so a slanted line drawn with them looks like a staircase. Anti-aliasing softens those staircases by mixing colors along the edge, so the line looks smooth from a normal viewing distance.
It works a little like squinting at a mosaic: the hard steps blend into a clean curve. The trade-off is speed and sharpness, because smoother edges cost the graphics card extra work, and some methods make the whole picture look slightly blurry.
A concrete example
A player runs a modern open-world game at 1440p on a mid-range graphics card. With anti-aliasing switched off, power lines and tree branches shimmer constantly as the camera pans, and building edges show visible stair steps. Switching to FXAA removes the steps but leaves the flicker and makes distant text on signs harder to read.
The player then selects the game’s TAA option with a sharpening slider at a low value. The image becomes stable in motion, with only slight ghosting behind fast cars. Finally, the player tries the upscaler’s native anti-aliasing mode, which costs about the same performance as TAA but keeps foliage detail and removes most ghosting. That mode becomes the final choice, and the frame rate stays above 60 frames per second.