StreamLive Pro

Remove a black background from a logo with the luma key

Logo shows in a black box on air? The luma key in the browser studio turns the dark parts transparent. Where the slider is, what value to start with, and its limits.

Updated November 5, 2026 · 4 min read

When a logo or graphic arrives with a black background, the luma key in the browser studio removes it. Open the input's settings, go to the Colour Key tab and raise the Luma Key slider: every part of the picture darker than the slider becomes transparent, and whatever is below shows through. It works on Program, on overlay channels and on layers, and it does not touch the input's position or its green-screen settings.

Before you start

• The browser studio. Open Live stream and choose Browser Studio, or work in Podcast. The luma key is in both studios, on every plan, including the trial.
• The logo as an input. Add it with the Logo tile, or as a picture or video through Add input. Steps: Add a logo and overlays to your live stream.
• A file with a truly dark background. The key works by brightness, not by colour. A pure black background keys cleanly. A dark grey or a noisy, compressed background needs a higher value and leaves rough edges.
• Better still, a file with transparency. A PNG, WebP or SVG with a transparent background needs no key at all. Use the luma key when that file is not available, for example a logo cut from a video or a graphic exported on black.

Steps

1. Open the input's settings. Click the gear on the logo's tile, or double-click the tile. A double-click opens the settings and never puts the input on air.
2. Go to the Colour Key tab. The tab buttons are along the top of the window: General, Colour Key, Position, Layers.
3. Scroll to Luma Key. It is the last slider on the tab, under the chroma key controls. It goes from 0 (off) to 100.
4. Raise it slowly. Start low, for example 10, and watch the Result preview and the Preview monitor. Stop as soon as the black box is gone.
5. Check the dark parts of the logo itself. Everything darker than the slider disappears, including black letters inside the logo. If letters start to fade, lower the value.
6. Click Done. Changes apply while you move the slider; Done keeps them and Cancel puts back what was there when you opened the window.
7. Put the logo on an overlay channel. Click an overlay number (1 to 8) on the tile so it stays over every camera: Overlay channels 1 to 8 and their keys (F1 to F8).

How the luma key decides

The key is drawn by the graphics card when the browser allows it, and by the processor when it does not, so the result is the same on every computer. Because it is part of the picture the studio sends, every network and the recording see the logo without its box.

Luma key or colour key

Both keys can be on at the same time on one input. The difference between the two, explained: Chroma key and luma key: what they are and when to use them.

What can go wrong

• A grey haze stays where the black was. The background is not pure black. Raise the slider a little, or export the logo again on pure black.
• Holes appear inside the logo. Dark parts of the logo are below the slider. Lower the value, or use a version of the logo with a transparent background.
• Rough or flickering edges. The file is heavily compressed (a JPG or a low-bitrate video). A cleaner export fixes it better than a higher value.
• The black box is still on air. The key is on another input, or the change was cancelled. Open the settings of the tile that is on air and check the slider.
• The Remove green screen button disappeared from the tile. That is expected: the button is offered only for inputs with no key on.

More about the settings window: Input settings in the browser studio, tab by tab. Building a background behind a person instead: How to set up a green screen virtual studio for live streams.

Frequently asked questions

Where is the luma key in StreamLive Pro?

In the browser studio, in the settings of each input: the gear on the tile, the Colour Key tab, the Luma Key slider at the bottom.

What value should I use?

Start around 10 and raise it until the black box is gone. The darker and cleaner the background, the lower the value you need.

Does the luma key work on a video logo?

Yes. It works on pictures, videos and cameras. For a moving logo, a WebM video with its own transparency avoids the key altogether.

Can I remove a white background with it?

No. The luma key removes dark parts only. For a white background, export the logo as a PNG with a transparent background.

Will the networks see the logo without the box?

Yes. The key is applied inside the studio before the picture is sent, so every network and the recording get the keyed logo.

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