Best Downscale Filter in OBS (Bilinear vs Bicubic vs Lanczos)

When you output at a lower resolution than your canvas (e.g. 1080p canvas, 720p output), OBS uses a downscale filter. The options are Bilinear, Bicubic, and Lanczos. Here’s what each does and when to use it.

What Each Filter Does

Bilinear is the fastest and simplest. It averages nearby pixels. Quality is the softest of the three but good enough for many streams.

Bicubic uses a larger sample and produces sharper results than Bilinear with a bit more CPU use. It’s a solid middle ground.

Lanczos uses the most sampling and typically gives the sharpest downscale. It also uses the most CPU/GPU. Best when you have headroom and care about fine detail.

When to Use Bilinear (Low-End PC)

If you’re on a low-end PC or already near encoding or FPS limits, choose Bilinear. The quality difference at typical stream bitrates is small, and saving CPU/GPU can help avoid dropped frames or stutter.

When to Use Lanczos (High-End)

If you have a strong GPU (e.g. RTX) and use NVENC, or a dedicated streaming PC, Lanczos can give a slightly sharper image when downscaling (e.g. 1080p to 720p). Use it when you’re not constrained by performance.

Performance Impact

Bilinear has the lowest impact; Lanczos the highest. The difference is usually a few percent CPU or GPU. For most single-PC streamers the encoder (NVENC or x264) matters more than the filter. If you’re stable, try Bicubic or Lanczos; if you’re dropping frames, try Bilinear.

Full setup: Best OBS Settings for Twitch and Best OBS Settings 2026.

FAQ

Which downscale filter is best?

For best quality with headroom: Lanczos. For a balance of quality and performance: Bicubic. For lowest CPU/GPU use: Bilinear. Most streamers are fine with Bicubic.

Does Lanczos use more CPU?

Yes. Lanczos does more work per frame when downscaling than Bicubic or Bilinear. The impact is usually small compared to encoding; try it and check OBS stats. If you see encoding lag, switch to Bicubic or Bilinear.

Is Bicubic good enough?

Yes. Bicubic is a good default: sharper than Bilinear, lighter than Lanczos. At typical stream bitrates the visible difference between Bicubic and Lanczos is often minimal.