Set your canvas size before you start recording

OBS captures whatever size you tell it to capture, but the mismatch between what you see and what gets recorded usually comes from a gap between your canvas size (what OBS thinks it is recording) and your source size (what your screen actually is). If your recording looks zoomed in, zoomed out, or off-center, you need to match these two numbers.

The fastest fix is to set your canvas size to match your monitor's resolution before you add any sources. Open OBS, go to Settings (bottom right), click Stream, and look for Canvas Resolution. Set it to the same resolution as your monitor — if you have a 1920×1080 monitor, set the canvas to 1920×1080. If you have a 2560×1440 monitor, set it there instead.

Once your canvas matches your monitor, add your screen capture source. OBS will usually scale it correctly on its own. If it does not, you can manually resize the source by right-clicking it in the Sources panel and selecting Scale with Source or by dragging the corners of the preview.

Key Takeaways

  • Canvas size in OBS Settings should match your monitor's actual resolution — check your display settings if you are unsure what that is.
  • If your screen capture appears zoomed in or out, the canvas and source sizes are mismatched, and fixing the canvas size first usually solves it.
  • You can manually resize a screen capture source by right-clicking it and selecting Scale with Source, or by dragging its corners in the preview.
  • High-resolution monitors (2560×1440 or higher) may require you to set a lower canvas size if your computer cannot handle the bitrate, but this will make your recording smaller.

Understanding canvas size versus source size

OBS works with two separate size settings, and confusing them is the main reason recordings come out wrong. Your canvas is the frame OBS is building — think of it as a blank piece of paper. Your source is what you are putting on that paper — your screen, a window, a webcam, whatever.

If your canvas is 1920×1080 but your screen is 2560×1440, OBS has to squeeze your screen down to fit the smaller canvas. Everything looks smaller and may be blurry. If your canvas is 2560×1440 but your screen is 1920×1080, OBS stretches your screen to fill the canvas, making it look pixelated and blurry in the opposite direction.

The solution is to make them the same size. Your canvas should almost always match your monitor's resolution. If you have multiple monitors, pick the one you are recording from and use its resolution.

How to check your monitor's actual resolution

On Windows, right-click your desktop and select Display Settings. Scroll down to Display Resolution and note the number — it will say something like 1920 × 1080 or 2560 × 1440. That is the number you need to put in OBS.

On Mac, click the Apple menu, select System Settings, then Displays. Look for Resolution. If you see "Scaled" options, pick the one that says "Default" — that is your actual resolution.

Once you have that number, go back to OBS, open Settings, click Stream, and set Canvas Resolution to match. Then close Settings and add your screen capture source.

Resizing a source that is still the wrong size

If you have already added a screen capture source and it is still too big or too small, you can resize it without deleting and re-adding it. Right-click the source in the Sources panel (the list on the left side of OBS) and look for Scale with Source. Click that, and OBS will automatically fit the source to your canvas.

If Scale with Source does not exist or does not work, you can resize manually. Click the source in the preview window (the big black area in the middle) and drag the corners outward to make it bigger or inward to make it smaller. Hold Shift while dragging to keep the proportions correct and avoid stretching.

If the source is off-center after resizing, click and drag the source itself (not the corners) to move it where you want it. You can also right-click the source and select Transform to access alignment tools if you want to center it precisely.

What to do if your computer cannot handle your monitor's resolution

Some older computers or laptops cannot record at their monitor's full resolution without dropping frames or overheating. If you see stuttering, lag, or your CPU usage spike to 100 percent when you start recording, your computer may be struggling.

You have two options. The first is to lower your bitrate in Settings under Output — this makes the file smaller and uses less CPU, but the video will be less sharp. The second is to lower your canvas resolution to something smaller, like 1280×720 if your monitor is 1920×1080. This records less data and is faster, but your recording will be smaller than your screen.

Test both approaches and see which one gives you smooth recording without lag. If you lower the canvas, remember that it will not match your monitor size anymore, so you may see black bars or stretching in the preview — that is normal and will not affect the final recording.

Fixing stretched or distorted screen capture

If your screen capture looks stretched, squished, or distorted, the source aspect ratio does not match your canvas. This usually happens when you manually resize a source without holding Shift, or when you use a canvas size that does not match your monitor.

The quickest fix is to right-click the source, select Transform, and then select Fit to Screen. OBS will resize the source to fit your canvas without stretching it. If that does not work, delete the source and add it again, making sure your canvas size is correct first.

If you see black bars on the sides or top and bottom of your recording, that is usually correct — it means OBS is preserving the aspect ratio and not stretching anything. The bars will only appear if your canvas and source have different shapes (like a 16:9 canvas with a 4:3 source).

Using a lower resolution for faster performance

If you are recording gameplay, streaming, or doing anything that demands a lot from your computer, you may want to record at a lower resolution than your monitor supports. This frees up CPU and GPU power for the thing you are recording.

To do this, set your canvas to a lower resolution than your monitor — for example, 1280×720 instead of 1920×1080. Then add your screen capture source. OBS will scale it down automatically, and your recording will use less data and process faster.

The trade-off is that your recording will be smaller and less detailed. Text may be harder to read, and small details may disappear. Test a short recording at your chosen resolution to see if it is sharp enough for what you need before you record something important.

Frequently Asked Questions

Why does my recording look zoomed in even though I set the canvas size correctly?

The source may still be scaled larger than the canvas. Right-click the source in the Sources panel and select Scale with Source, or manually drag the corners inward while holding Shift. If the source is still too big after that, check that you are looking at the right monitor resolution — some systems report resolution differently depending on scaling settings.

Can I record at a different resolution than my monitor?

Yes. Set your canvas to whatever resolution you want in Settings, then add your screen capture source. OBS will scale your screen to fit the canvas. Lower resolutions record faster and use less storage, but text and small details may be harder to see in the final video.

What if I have two monitors and want to record only one?

When you add a screen capture source, OBS will ask which monitor to capture. Pick the one you want. Set your canvas size to match that monitor's resolution, not both monitors combined. If you want to record both monitors, set your canvas to the combined width and height, but this uses significantly more CPU.

Why is my recording blurry even though the size looks right?

Blurriness usually means your canvas is larger than your monitor's resolution, so OBS is stretching a smaller image to fill a bigger frame. Check that your canvas size matches your monitor exactly. If it does, try lowering your bitrate in Output settings — a bitrate that is too low will make video look soft and blurry.

How do I know if my bitrate is too low?

Record a short test video and play it back. If it looks blocky, fuzzy, or like it is losing detail in fast-moving parts, your bitrate is too low. Increase it in Settings under Output. Start with 6000 to 8000 kbps for 1080p and adjust up or down based on what you see in the test.