adobe premiere pro chroma key

The short answer: Premiere Pro's Ultra Key effect has five controls that matter, and you touch them in a specific order: key colour, transparency, spill suppression, matte choke, and matte soften. Skip the order and you will spend twice as long fighting the matte. If Ultra Key cannot produce a clean result on difficult footage, send the clip to After Effects — the round trip is one right-click and gives you the Roto Brush and full masking tools.

This page is specifically about Premiere Pro. For the general keying principles that apply to every editor — why tolerance works the way it does, why spill happens, how chroma subsampling affects edges — see the green screen removal guide. For help choosing between editors, see the green screen editing software comparison.

Where to find Ultra Key

Ultra Key ships with every version of Premiere Pro. Open the Effects panel (Window > Effects if it is not visible), and navigate to Video Effects > Keying > Ultra Key. Drag the effect onto your green screen clip in the timeline. The controls appear in the Effect Controls panel, docked by default in the upper left of the interface.

Before you touch any settings, put your playhead on a frame where the subject is clearly visible and the green screen fills most of the background. This is the frame you will key on, and it should be representative of the whole clip — if the lighting changes during the shot, pick the brightest, most evenly lit frame.

Step 1: Sample the key colour

Under the Ultra Key effect, find the Key Colour swatch. Click the eyedropper icon next to it, then click on the green screen in the Program monitor — not on the subject, not on a corner or a fold, but on a flat, evenly lit area of the screen directly behind and beside the subject. The exact pixel you pick matters: if you sample a shadow or a highlight, the keyer will use a colour that does not represent the screen, and you will spend the rest of the process fighting the tolerance.

If the screen is lit unevenly, sample from the brightest area first. You can add a second Ultra Key instance or use a garbage matte for the darker areas (see below).

Step 2: Set transparency (tolerance)

The Transparency setting is tolerance under a different name — it controls how far a pixel's colour may drift from the key colour and still be treated as background. Start at the default and raise it slowly until the green disappears. Then drop it back slightly until the subject stops losing chunks. The useful range is narrow: a few percent either way changes the result more than you expect.

Switch the Output menu (at the top of the Ultra Key controls) to Alpha Only. This shows your matte as black and white — white is subject, black is background, grey is semi-transparent. This is the only honest way to evaluate a key: the composite view hides problems that the matte view makes obvious. Look for grey areas along the edges, holes in the subject, and chunks of background that are not fully black.

Step 3: Spill suppression

Switch the Output back to Composite, then find the Spill Suppression slider under the Matte Cleanup section. Raise it slowly while watching the subject's hair, shoulders, and anything light-coloured. Too little leaves a green rim; too much drains the colour from the subject's skin and makes them look grey. The right amount removes the green cast without affecting the rest of the image.

Spill is the problem people blame on the keyer when the real cause was the shoot: the subject stood too close to the screen, and green light bounced onto them. No tolerance setting removes it because those pixels are part of the subject, not the background. The green screen editor guide covers spill measurement and the three despill methods in detail.

Step 4: Matte cleanup — choke and soften

Once the key and spill are set, the Matte Cleanup section has two controls that tighten the edge:

• Choke. Shrinks the matte inward. Use it when there is a fringe of background pixels around the subject that tolerance did not remove. Small values — one or two — are usually enough. Too much choke eats into the subject's edges and makes them look thin.
• Soften. Blurs the matte boundary. On 1080p footage, one to three pixels is usually enough. Too much soften makes the subject look like it is wrapped in plastic and causes the matte to bleed into the new background.

Both controls are cosmetic — they hide a slightly imperfect key. They cannot fix a badly lit screen or a wrong key colour. If you find yourself pushing choke or soften to high values, go back to steps 1 and 2.

Step 5: Garbage matte (when you need it)

If the screen is lit unevenly or there are areas of the frame the keyer cannot handle, add a garbage matte. In the Effects panel, find Video Effects > Keying > Garbage Matte (or Four-Point, Eight-Point, or Sixteen-Point Garbage Matte depending on how complex the shape needs to be). Apply it before Ultra Key in the effect stack — Premiere processes effects top to bottom, so the garbage matte runs first and limits what the keyer has to solve.

Draw a rough shape around the subject, excluding the problem areas. The keyer then only has to produce a clean matte on the edges inside that shape, not on the whole frame. For unevenly lit screens, this is the difference between a usable key and a hopeless one.

When to send the clip to After Effects

Ultra Key handles most green screen footage well. It does not handle:

• Fine hair against a busy background. Ultra Key's edge is a simple alpha; After Effects' Refine Edge tool does soft-edge extraction that handles individual strands.
• Multiple subjects crossing each other. Ultra Key applies one matte to the whole frame; After Effects lets you mask each subject separately and track them independently.
• Rotoscoping. When there is no green screen at all and you need to cut the subject out manually, After Effects' Roto Brush is the right tool. See the video background remover guide for the broader context.

The round trip is one step: right-click the clip in the Premiere Pro timeline, select Replace with After Effects Composition. After Effects opens with the clip loaded, and when you save the After Effects project, the result updates on the Premiere Pro timeline automatically. No rendering, no importing, no syncing.

Exporting with transparency

Once the key is clean, exporting with transparency requires choosing a format that stores alpha. From Premiere Pro's export dialog (File > Export > Media):

• WebM with VP9. Works in Chromium and Firefox. You may need a plugin for the WebM exporter in older versions of Premiere Pro; the current version includes it.
• QuickTime with ProRes 4444. The standard for moving transparent video between editors. Large files but exact alpha.
• PNG or TIFF sequence. Each frame is a separate image with alpha. Cumbersome but maximally compatible.
• Not H.264 or H.265. The base profiles of both codecs have no alpha channel. A transparent export to H.264 comes back with a flat black background.

If the clip is going to social media, the platform re-encodes the upload and transparency does not survive. Composite the new background in Premiere Pro and export a normal opaque file.

Quick answers

Related reading: the four keying settings in order (general guide), choosing the right green screen editor, rescuing unevenly lit footage, 12 checks before you export, and removing a video background without a green screen.