> ## Content Index
> Fetch the complete content index at: https://aftereffectsclub.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# How to scale a layer to fill the frame in After Effects
- URL: https://aftereffectsclub.com/scale-to-fill-frame-after-effects/
- Published: 2026-11-01T14:24:55.000Z
- Updated: 2026-11-05T20:40:31.000Z
- Description: Choose Fit To Comp Width or Height to fill the frame without stretching, move the crop with Position and check raster quality and pixel aspect ratio.
- Author: Ethan Brooks
- Tags: Timeline, layers and audio

To fill the frame in After Effects without stretching, select the layer and choose Layer > Transform > Fit To Comp Height if the layer is wider than the composition, or Fit To Comp Width if it is narrower or taller. Both commands preserve the layer's proportions, centre it and crop any overhang. Plain Fit To Comp stretches the image when the layer and composition have different shapes.

I'd start with a fit command because it gives the exact edge-to-edge scale; Position then decides which part of the picture stays visible. [Adobe's layer-scaling instructions](https://helpx.adobe.com/after-effects/desktop/work-with-layers/layer-properties/layer-properties.html?ref=aftereffectsclub.com) distinguish the three fit commands and explain how to constrain Scale when adjusting it by hand.

## The comp and the layer before the first command

Set the composition size and layer state before fitting:

- **The comp is open at the size you will deliver.** Ctrl + K (Command + K on macOS) opens Composition Settings, where Width, Height and Pixel Aspect Ratio say what the frame is. If those are wrong, change the comp first, as described further down; a fit made now would have to be made again.
- **The layer is selected in the Timeline panel.** With Fit To Comp Width or Height, each selected layer is fitted separately and keeps its own aspect ratio, so one command can handle a stack of stills of different shapes.
- **The layer has a Scale property.** Footage, stills and solids do; camera, light and audio-only layers have none. The steps below use a square-pixel composition and an unrotated 2D footage or image layer with square pixels, no parent, no mask and the Scale stopwatch off. Save a project copy before changing an existing animation.
- **Trimming can wait or come first.** Scale without keyframes holds one value along the whole layer bar, so it makes no difference whether you [cut the clip](https://aftereffectsclub.com/cut-clip-after-effects/) before or after filling the frame.

At this point the layer usually sits at Scale 100%, and the parts of the frame it does not reach show as empty bands along one pair of edges or all four.

## Wider or narrower than the comp: which command fills

Compare shapes, not pixel counts. Divide width by height for the layer and for the comp: a 1920 × 1080 comp gives about 1.78, a 4:3 photo gives 1.33 even when it holds far more pixels than the comp, and 2.39:1 cinema footage gives 2.39.

- **Layer number higher than the comp's (wider):** Fit To Comp Height. The layer's top and bottom meet the frame, and its left and right edges run past the sides. Fit To Comp Width on the same layer leaves empty bands above and below. A 16:9 shot dropped into a 9:16 vertical comp belongs here.
- **Layer number lower (narrower or taller):** Fit To Comp Width. The sides meet the frame, and the top and bottom run past it. Fit To Comp Height would leave bands at the sides. A 4:3 still, a square photo, a portrait photo or a phone video in a 16:9 comp belongs here.
- **Same number:** Fit To Comp, Fit To Comp Width and Fit To Comp Height all give the same result, as with a UHD 3840 × 2160 clip in a 1920 × 1080 comp.

No numbers to hand? Apply Fit To Comp Height and look at the sides of the frame. Bands there mean the layer is narrower than the comp, so apply Fit To Comp Width instead; no bands means Height was the right call.

When the shapes differ, filling crops part of the picture, and the amount grows with that difference. A 16:9 shot filling a 9:16 comp keeps a vertical slice a little under a third of its width, and a vertical phone video filling a 16:9 frame keeps a horizontal strip a little under a third of its height. When that strip would cut through the subject, the bands are the better result: use the command that leaves them and put a background layer underneath.

## Fill the frame with Fit To Comp Height or Fit To Comp Width

1. Select the layer in the Timeline panel. With the Selection tool active, its handles appear in the Composition panel and mark the layer's edges.
2. Choose Layer > Transform > Fit To Comp Height for a wider layer, or Layer > Transform > Fit To Comp Width for a narrower or taller one. The default keys in [Adobe's keyboard shortcut reference](https://helpx.adobe.com/after-effects/desktop/get-started/keyboard-shortcuts/keyboard-shortcuts-reference.html?ref=aftereffectsclub.com) are Ctrl + Alt + Shift + G (Height) and Ctrl + Alt + Shift + H (Width) on Windows, Command + Option + Shift + G and Command + Option + Shift + H on macOS. The layer moves to the centre of the comp and grows or shrinks until one pair of its edges sits exactly on the frame.
3. Check the result. Press S to show only Scale: both values are the same number, which is what a preserved aspect ratio looks like on the property, and no band remains anywhere along the frame. If a band does remain, the layer had the other shape; apply the other command.
4. Choose what gets cropped. Because the layer is centred, the overhang is split evenly between two edges. To keep more of one side, press P to show only Position and drag the x value for a wide layer or the y value for a tall one. Watch the handles of the far edge, which sit past the frame; if they are out of view, click the Composition panel tab, then press the comma key to zoom out and Shift + / on the main keyboard to zoom back to fit (the same keys on macOS and Windows). Once that edge crosses into the frame, a band opens on that side, so stop just before it.

If the subject moves and the crop has to follow it, a single Position value is not enough. Adobe's notes on scaling describe the easiest pan and scan over a large image as animating Anchor Point and Scale, which turns the fill into keyframes rather than one setting.

## Fit To Comp stretches unless the shapes already match

Fit To Comp makes the layer's width equal the comp's width and its height equal the comp's height, as two separate scale values. When layer and comp share a shape, the two values come out equal and nothing distorts. When the shapes differ, the picture is stretched or squeezed: faces widen, wheels turn into ellipses, type gets heavier in one direction.

![Three wide frames holding the same narrower picture of a round clock above a horizon: with Fit To Comp Height dark bands fill both sides; with Fit To Comp Width the picture covers the frame, the clock is larger and still round, and hatched strips hang outside the frame above and below; with Fit To Comp the picture covers the frame but the clock is stretched into a wide ellipse](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-figure1-provenance-34ff4dbb548668da.webp)

The same narrower shot in a wide comp, three ways. Only Fit To Comp Width fills the frame without changing the clock's shape. [Open the three fit results at full size](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-figure1-provenance-34ff4dbb548668da.webp?ref=aftereffectsclub.com) to compare the shapes and edge bands.

The quickest check for an accidental stretch is the property itself: press S, and two different numbers in Scale mean the layer no longer has its own shape. A stretch can still be the right call for a texture, a gradient or a blurred background plate where nobody can see the distortion and the edges matter more than the content. For anything with a recognisable shape, stay with Width or Height.

## Scale by hand with Constrain Proportions on

Type Scale by hand when the fit commands don't give the extra size you need. A value a little above the fill leaves room for the layer to drift in a slow push without a band appearing at the edge. The steps all work on the Scale property of the selected layer:

1. Press S to show only Scale in the Timeline panel.
2. Check the Constrain Proportions icon to the left of the Scale values. With it on, a new value in either field carries over to the other. Alt-click (Windows) or Option-click (macOS) on the icon turns it on and sets the height to match the width, which repairs a layer that Fit To Comp has stretched.
3. Type a value, or scale in the Composition panel with the Selection tool. Dragging without Shift is how a stretch sneaks in: a corner handle scales freely and a side handle changes one dimension only. So hold Shift, then drag any handle to scale proportionally.
4. For fine steps, hold Alt (Option on macOS) and press plus or minus on the numeric keypad to change Scale by 1%; add Shift for 10%. Mac laptops and compact keyboards without a numeric keypad need the typed value or the Shift-drag instead.
5. For an exact size in pixels, right-click (Windows) or Control-click (macOS) the Scale value, choose Edit Value and switch the units to pixels, then type the size the filling axis should reach: the comp's height for a wide layer, its width for a tall one. Include Pixel Aspect Ratio shows those dimensions in terms of the comp's pixel aspect ratio. Confirm the dialog and the layer takes the new size.

![Scale row with the Constrain Proportions chain beside two equal percentage values](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-scale-controls-owner130-23b06c0b15cc.webp)

Press S to reveal Scale, then use Constrain Proportions so both axes change together. [Open the Scale controls at full size](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-scale-controls-owner130-23b06c0b15cc.webp?ref=aftereffectsclub.com).

Scaling always happens around the layer's anchor point. A layer whose anchor sits off centre grows toward one side, so after a manual change look at all four edges again and slide Position with P as in the fill steps. To start over on this static layer, right-click or Control-click the name Scale, not its value, and choose Reset. On an animated property, Reset adds a default-value keyframe at the current time instead of clearing the animation.

## When the comp is the wrong size, change the comp

If every shot in the project shares one shape and the comp has another, fitting each layer treats the symptom. I'd fix the comp first: one change in Composition Settings, instead of a fit command on every layer now and on every shot added later. Adobe's [composition settings guide](https://helpx.adobe.com/after-effects/desktop/work-with-compositions/composition-settings/composition-basics.html?ref=aftereffectsclub.com) also recommends settling frame size and frame aspect ratio when the comp is created, because a late change can affect the final output, so make the change before any animation depends on where the edges are.

- **Build the comp from the footage.** Select the footage item in the Project panel and choose File > New Comp From Selection, press Alt + \\ on Windows or Command + \\ on macOS, or drag the item onto the Create a new composition button at the bottom of the Project panel. The new comp takes its frame size and pixel aspect ratio from the footage, so the layer fills it at Scale 100%. With several items selected, the New Composition from Selection dialog asks whether to make a Single Composition and which item to take dimensions from in Use Dimensions From.
- **Change an existing comp.** Composition > Composition Settings (Ctrl + K or Command + K) holds Width, Height, Pixel Aspect Ratio and a Preset menu that includes presets for social platforms. Under Advanced, the Anchor arrow buttons set the corner or edge the layers stay pinned to while the comp changes size.
- **Crop the comp to a layer.** When one 2D layer already frames the picture you want, select it and choose Crop Comp to Selected Layer(s) Bounds from the Composition menu, or from the right-click menu (Control-click on macOS) of the selected layer in the Timeline or Composition panel. The comp is cropped to the visible area of that layer when the layer is smaller than the frame, or extended to include it when the layer runs past the frame.
- **Scale the whole comp.** When the composition itself has to grow or shrink as a whole, File > Scripts > Scale Composition.jsx scales the entire composition. Unlock every layer first, because the script fails on a locked one.

![Lower part of the layer context menu with Crop Comp to Selected Layer(s) Bounds selected](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-crop-layer-bounds-owner130-625481c6d674.webp)

Crop Comp to Selected Layer(s) Bounds uses the selected 2D layer to set the composition bounds. [Open the crop command at full size](https://storage.ghost.io/c/93/1e/931ecadb-86fa-4092-9a2d-733ed6274523/content/images/2026/11/scale-to-fill-frame-after-effects-crop-layer-bounds-owner130-625481c6d674.webp?ref=aftereffectsclub.com).

## Above 100%: what an enlarged layer loses

After a fit, read the Scale value. Below 100% the layer drops pixels it had to spare; above 100% it has to stretch the ones it has, and Adobe's notes on scaling warn that a raster layer enlarged by a large factor can look blocky or pixelated, while scaling down sometimes softens it slightly. The layer's own scaling cannot put back detail the source never held, so each option below trades something:

- **A larger source.** If the footage or still exists at a higher resolution, importing that version beats every setting in this list.
- **Detail-preserving Upscale.** Adobe lists this effect in the [Distort category](https://helpx.adobe.com/after-effects/desktop/apply-effects-and-animation-presets/effects-and-animation-presets/effect-list.html?ref=aftereffectsclub.com) and describes [the Detail-preserving Upscale effect](https://helpx.adobe.com/after-effects/desktop/apply-effects-and-animation-presets/list-of-effects/detail-preserving-upscale-effect.html?ref=aftereffectsclub.com) as scaling images by large amounts while keeping sharp lines and curves sharp, for jumps such as SD to HD or HD to digital cinema. It carries its own Fit To Comp Width and Fit To Comp Height controls, a Scale control that does not go below 100%, Reduce Noise and Detail. Two costs come with it: high Detail values can add ringing or halo artifacts along edges, and the effect is slower than the layer's own bilinear or bicubic scaling. I'd let either the effect or the layer's Scale do the enlarging, not both, so the size lives in one place and a later change happens there.
- **Vector layers.** A layer made from an Illustrator, SWF, EPS or PDF file keeps its quality above 100% when Continuously Rasterize is on. Know the cost before switching it on: [continuously rasterizing a layer](https://helpx.adobe.com/after-effects/desktop/work-with-layers/manage-layers/layers.html?ref=aftereffectsclub.com) re-rasterizes it for every frame, which can raise render time, and changes its render order, so effects on it may look different afterwards. The switch is the one it shares with Collapse Transformations in the Timeline panel. Shape layers and text layers are always continuously rasterized, so they need no switch.
- **Layer quality.** With the layer's quality at Best (Layer > Quality, or the Quality switch), sampling can be Bilinear, with Alt + B on Windows or Option + B on macOS, or Bicubic, with Alt + Shift + B or Option + Shift + B. Adobe notes that bicubic is not always the higher-quality choice and can show ringing at hard edges, so compare both on a frame with sharp edges.

The Composition panel is a working view, so judge softness again on a frame of the rendered file at full size once you [export the finished video](https://aftereffectsclub.com/export-after-effects-video/).

## Filled but still stretched: the pixel aspect ratio

If a fitted layer shows two equal Scale values and still looks too wide or too narrow, the pixels themselves may be the wrong shape. Pixel aspect ratio is the width-to-height ratio of one pixel, and nonsquare pixels shown on a square-pixel display without correction look distorted, with circles turning into ellipses. To see how After Effects reads the file, select it in the Project panel and open Interpret Footage from the button at the lower left of the Project panel, through File > Interpret Footage > Main, or with Ctrl + Alt + G (Command + Option + G on macOS).

Adobe's page on [pixel aspect ratio in Interpret Footage](https://helpx.adobe.com/after-effects/desktop/work-with-footage-items/import-and-interpret-footage-items/importing-interpreting-footage-items.html?ref=aftereffectsclub.com) names the case for a reset: a square-pixel file that happens to have D1 or DV dimensions, such as a 720 × 480 image, gets read as nonsquare, and setting Pixel Aspect Ratio to Square Pixels corrects it. Leave the tag alone on footage that really has nonsquare pixels; once every item is interpreted correctly, footage with different pixel aspect ratios can share one comp. After a change, apply the fit command again, since the layer now occupies a different width in the comp.

## An expression that keeps the layer filling the comp

A fit command sets Scale once. If the comp's size may still change, or the footage may be swapped for a version with other dimensions, an expression on Scale can recompute the fill from the sizes themselves, and the comp's Width and Height stay the one place to edit. Run Fit To Comp Width or Height once first so the layer is centred, then Alt-click (Windows) or Option-click (macOS) the stopwatch next to Scale, or select Scale and choose [Animation > Add Expression](https://helpx.adobe.com/after-effects/desktop/work-with-expressions/edit-expressions/edit-expressions.html?ref=aftereffectsclub.com), and enter:

```
s = Math.max(
  thisComp.width / width,
  thisComp.height / height
) * 100;
[s, s]
```

Read it piece by piece. In [Adobe's expression language reference](https://helpx.adobe.com/after-effects/desktop/work-with-expressions/expression-language-reference/expression-language-reference.html?ref=aftereffectsclub.com), thisComp.width and thisComp.height are the comp's frame size in pixels, and width and height on their own belong to the layer, because the layer is the default object (width returns the same value as source.width). Each division says how far the layer must scale to reach one pair of edges. Math.max takes the larger factor, which covers the frame and lets the other axis overhang, the same choice the right fit command makes. Swap in Math.min and the layer fits inside the frame with bands instead. Multiplying by 100 turns the factor into the percentage Scale expects, and \[s, s\] writes that one number to both axes.

The formula follows from those definitions and holds when both the composition and the 2D footage or image layer use square pixels. The layer must be centred and unrotated, with no parent or mask and its anchor point at its centre. Keep this version to footage and stills; text, shapes and 3D perspective need different bounds. To check it on your own comp, change Width in Composition Settings with the Anchor under Advanced set to the centre, and the layer should still reach every edge. For a layer that also moves and must keep covering the frame on every frame, [Dan Ebberts' answer on Adobe Community](https://community.adobe.com/questions-529/auto-scale-image-to-always-fill-composition-when-changing-its-position-44232?ref=aftereffectsclub.com) samples Position across the composition and keeps the largest required scale. He warns that it will be slow if the comp is long and suggests converting the expression to keyframes once the result is right.