Replay Buffer

What Is a Replay Buffer?

A replay buffer continuously keeps recent video and audio, letting you save a clip after an event happens. It stores only a rolling time window in temporary memory, replacing the oldest footage until you save it.

Tools such as OBS Studio use replay buffers for gameplay highlights, demos, tutorials, and bug reports. Saved clips become separate files while the buffer keeps running.

How a Replay Buffer Works

It captures recent moments without saving an entire session.

1. Software captures and encodes video and audio continuously.
2. It keeps only the configured recent duration.
3. New footage overwrites the oldest footage.
4. You press a hotkey or control to save a replay.
5. The software writes that segment as a separate clip file.

How to Turn On Replay Buffer in OBS Studio

Settings can vary by OBS version, but the process is similar.

1. Open Settings and find Replay Buffer under Output.
2. Enable it and choose a replay duration and memory limit.
3. Choose a local folder for saved clips.
4. Assign a Save Replay hotkey in Hotkeys settings.
5. Start Replay Buffer, then save a test clip.

Replay Buffer vs Full Recording vs NVIDIA Instant Replay

OBS can provide a similar function to the feature formerly called ShadowPlay. NVIDIA now commonly provides its capture overlay through the NVIDIA App.

Benefits of Using a Replay Buffer

It gives creators and testers more control over what they keep.

• Reduces storage used by uneventful footage.
• Captures unexpected moments quickly.
• Lets you choose a duration for the activity.
• Can preserve OBS scenes and selected audio sources.
• Documents software defects without recording all day.

Practical Limits: Does Replay Buffer Affect FPS?

Yes. Continuous capture and encoding use system resources and can affect FPS. Whether OBS puts more load on the CPU or GPU depends mainly on the selected encoder.

• Higher resolution, frame rate, and bitrate increase encoding demand.
• Longer buffers need more available memory.
• Saving a clip creates a short disk-writing workload.
• Hardware encoders can reduce CPU load but still use GPU resources.
• Test during real workloads and leave performance headroom.

Choosing Reliable Replay Buffer Settings

Set the duration around the event you need to capture, such as a short gameplay moment or longer product demonstration. Match the encoder to available hardware, save clips to a fast local drive, and use separate audio tracks when editing requires them. Before an important stream, test a clip and confirm its audio, timing, and destination folder.

Replay-aware capture can also help when planning video features during app design and development. Teams building video-enabled products with an AI app builder can use Emergent to create, test, and ship the surrounding application workflow.