反锯齿（英语：anti-aliasing，简称AA），也译为抗锯齿或边缘柔化、消除混叠、抗图像折叠失真等。它是一种消除显示器输出的画面中图物边缘出现凹凸锯齿的技术，那些凹凸的锯齿通常因为高分辨率的信号以低分辨率表示或无法准确运算出3D图形坐标定位时所导致的图形混叠（aliasing）而产生的，反锯齿技术能有效地解决这些问题。它通常被用在在数字信号处理、数字摄影、电脑绘图与数码音效等方面，柔化被混叠的数字信号。

In digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution. Anti-aliasing is used in digital photography, computer graphics, digital audio, and many other applications.