Performance Help & FAQ

This document will help you get the best performance from your GPU so your Kaps browser based renders are as fast as possible.

Table of contents

  1. GPU setup
  2. Issues (FAQ)
  3. Export tips

GPU setup

Windows — force Chrome onto NVIDIA

  1. Windows Settings → System → Display → Graphics → find or add chrome.exe → Options → High performance → Save
  2. NVIDIA Control Panel → Manage 3D Settings → Program Settings → Add chrome.exe → set Preferred graphics processor to High-performance NVIDIA → Apply
  3. Task Manager → end every chrome.exe process → relaunch Chrome fresh

Tip: NVIDIA Control Panel is more persistent than Windows Display Settings. Windows updates regularly reset the Display Settings preference — NVIDIA Control Panel survives reboots and Chrome updates. Set both for maximum reliability.

Enable Chrome hardware flags

  1. Go to chrome://flags → search encode → set Hardware-accelerated video encode → Enabled
  2. In chrome://flags → search blocklist → set Override software rendering list → Enabled → Relaunch Chrome

Verify it is working

  1. Go to chrome://gpu — find GL_RENDERER. It should say something like ANGLE (NVIDIA GeForce RTX ...), not Intel UHD
  2. Both Video Encode Acceleration and Video Decode Acceleration should say Hardware accelerated

macOS

  1. System Settings → Battery → turn off Low Power Mode while rendering
  2. Chrome → chrome://settings/system → enable Use hardware acceleration → Relaunch

Tip: Apple Silicon Macs (M1/M2/M3) use a unified GPU — hardware acceleration is always active.

Issues (FAQ)

Render is very slow — 3–5 fps

Chrome is using software encoding. Almost always caused by Chrome running on the integrated GPU (Intel UHD) instead of your discrete NVIDIA/AMD GPU.

Fix: See GPU setup above for step-by-step instructions.

Preview was 90 fps, now it is 20 fps

Chrome switched back to the Intel iGPU. This happens after Chrome background updates or long uptime sessions.

Fix: Task Manager → end all chrome.exe → relaunch. Set NVIDIA Control Panel → Program Settings to make this stick permanently.

GPU card shows NVIDIA but encoding is still slow

Chrome’s WebGL renderer and its media encoder can run on different GPU paths. NVIDIA showing in WebGL does not guarantee NVENC is active.

Fix: Full PC restart resets the GPU arbiter. Then set NVIDIA Control Panel immediately after.

Render started slow then sped up — is that normal?

Yes, completely normal. The source video decoder cold-starts with expensive seeks. As the buffer fills up over the first ~200 frames, decode time drops from ~200 ms to ~10 ms and the render accelerates.

The estimated time shown is based on the cold-start frame — usually 3–5× too pessimistic. Your actual render will finish much sooner.

Worked perfectly yesterday, slow today — nothing changed

Chrome silently auto-updates in the background. A new process can spawn without inheriting the previous GPU assignment.

Fix: Restart PC, then set NVIDIA Control Panel → Program Settings for chrome.exe. This binding persists across Chrome updates.

AV1 not working even after GPU fix

Some Chrome + driver combos block AV1 NVENC internally. The app automatically tries fallback codec configs and picks the fastest available.

To force it: chrome://flags → Override software rendering list → Enabled → restart Chrome. Or use Dev Panel → Codec → H264.

Export tips

Resolution Bitrate Use case
540p 2–4 Mbps Social / preview
720p 4–6 Mbps Standard
1080p 6–10 Mbps High quality
4K 20–40 Mbps Master / archival

Tip: For social media (TikTok, Instagram, YouTube Shorts) the platform re-encodes your video anyway — 8 Mbps at 1080p is plenty. Going higher wastes upload time with no visible benefit.

Codecs

Codec Notes
AV1 Best quality per MB. Uses RTX 4xxx NVENC for fast export. Falls back to fast software if NVENC unavailable.
H264 Most compatible. Hardware on any GPU, or fast software fallback. Use this if AV1 causes issues.
VP9 Good hardware support on Intel iGPU and NVIDIA. Alternative when AV1 NVENC is blocked.

Antialiasing

Leave ON for all text and caption content. Turn OFF only for a deliberate pixel-art look or to squeeze a few extra fps from the renderer.