diff --git a/src/client/lazy-app/Compress/index.tsx b/src/client/lazy-app/Compress/index.tsx
index 5c37caae..193aff6d 100644
--- a/src/client/lazy-app/Compress/index.tsx
+++ b/src/client/lazy-app/Compress/index.tsx
@@ -114,7 +114,7 @@ async function decodeImage(
       }
     }
     // Otherwise fall through and try built-in decoding for a laugh.
-    return await builtinDecode(signal, blob, mimeType);
+    return await builtinDecode(signal, blob);
   } catch (err) {
     if (err instanceof Error && err.name === 'AbortError') throw err;
     console.log(err);
diff --git a/src/client/lazy-app/util/canvas.ts b/src/client/lazy-app/util/canvas.ts
index 04b88a3d..9986205a 100644
--- a/src/client/lazy-app/util/canvas.ts
+++ b/src/client/lazy-app/util/canvas.ts
@@ -63,35 +63,17 @@ interface DrawableToImageDataOptions {
   sh?: number;
 }
 
-function getWidth(
-  drawable: ImageBitmap | HTMLImageElement | VideoFrame,
-): number {
-  if ('displayWidth' in drawable) {
-    return drawable.displayWidth;
-  }
-  return drawable.width;
-}
-
-function getHeight(
-  drawable: ImageBitmap | HTMLImageElement | VideoFrame,
-): number {
-  if ('displayHeight' in drawable) {
-    return drawable.displayHeight;
-  }
-  return drawable.height;
-}
-
 export function drawableToImageData(
-  drawable: ImageBitmap | HTMLImageElement | VideoFrame,
+  drawable: ImageBitmap | HTMLImageElement,
   opts: DrawableToImageDataOptions = {},
 ): ImageData {
   const {
-    width = getWidth(drawable),
-    height = getHeight(drawable),
+    width = drawable.width,
+    height = drawable.height,
     sx = 0,
     sy = 0,
-    sw = getWidth(drawable),
-    sh = getHeight(drawable),
+    sw = drawable.width,
+    sh = drawable.height,
   } = opts;
 
   // Make canvas same size as image
diff --git a/src/client/lazy-app/util/index.ts b/src/client/lazy-app/util/index.ts
index 89555a5b..fb5caea6 100644
--- a/src/client/lazy-app/util/index.ts
+++ b/src/client/lazy-app/util/index.ts
@@ -10,8 +10,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
-import * as WebCodecs from '../util/web-codecs';
 import { drawableToImageData } from './canvas';
 
 /** If render engine is Safari */
@@ -139,15 +137,7 @@ export async function blobToImg(blob: Blob): Promise<HTMLImageElement> {
 export async function builtinDecode(
   signal: AbortSignal,
   blob: Blob,
-  mimeType: string,
 ): Promise<ImageData> {
-  // If WebCodecs are supported, use that.
-  if (await WebCodecs.isTypeSupported(mimeType)) {
-    assertSignal(signal);
-    try {
-      return await abortable(signal, WebCodecs.decode(blob, mimeType));
-    } catch (e) {}
-  }
   assertSignal(signal);
 
   // Prefer createImageBitmap as it's the off-thread option for Firefox.
diff --git a/src/client/lazy-app/util/web-codecs/index.ts b/src/client/lazy-app/util/web-codecs/index.ts
deleted file mode 100644
index 7f2b1949..00000000
--- a/src/client/lazy-app/util/web-codecs/index.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-import { drawableToImageData } from '../canvas';
-
-const hasImageDecoder = typeof ImageDecoder !== 'undefined';
-
-export async function isTypeSupported(mimeType: string): Promise<boolean> {
-  if (!hasImageDecoder) return false;
-  // Some old versions of this API threw here.
-  // It only impacted folks with experimental web platform flags enabled in Chrome 90.
-  // The API was updated in Chrome 91.
-  try {
-    return await ImageDecoder.isTypeSupported(mimeType);
-  } catch (err) {
-    return false;
-  }
-}
-
-export async function decode(
-  blob: Blob | File,
-  mimeType: string,
-): Promise<ImageData> {
-  if (!hasImageDecoder) {
-    throw Error(
-      `This browser does not support ImageDecoder. This function should not have been called.`,
-    );
-  }
-  const decoder = new ImageDecoder({
-    type: mimeType,
-    // Non-obvious way to turn an Blob into a ReadableStream
-    data: new Response(blob).body!,
-  });
-  const { image } = await decoder.decode();
-  return drawableToImageData(image);
-}
diff --git a/src/client/lazy-app/util/web-codecs/missing-types.d.ts b/src/client/lazy-app/util/web-codecs/missing-types.d.ts
deleted file mode 100644
index 6e832db8..00000000
--- a/src/client/lazy-app/util/web-codecs/missing-types.d.ts
+++ /dev/null
@@ -1,60 +0,0 @@
-interface ImageDecoderInit {
-  type: string;
-  data: BufferSource | ReadableStream;
-  premultiplyAlpha?: PremultiplyAlpha;
-  colorSpaceConversion?: ColorSpaceConversion;
-  desiredWidth?: number;
-  desiredHeight?: number;
-  preferAnimation?: boolean;
-}
-
-interface ImageDecodeOptions {
-  frameIndex: number;
-  completeFramesOnly: boolean;
-}
-
-interface ImageDecodeResult {
-  image: VideoFrame;
-  complete: boolean;
-}
-
-// I didn’t do all the types because the class is kinda complex.
-// I focused on what we need.
-// See https://w3c.github.io/webcodecs/#videoframe
-declare class VideoFrame {
-  displayWidth: number;
-  displayHeight: number;
-}
-
-// Add VideoFrame to canvas’ drawImage()
-interface CanvasDrawImage {
-  drawImage(
-    image: CanvasImageSource | VideoFrame,
-    dx: number,
-    dy: number,
-  ): void;
-  drawImage(
-    image: CanvasImageSource | VideoFrame,
-    dx: number,
-    dy: number,
-    dw: number,
-    dh: number,
-  ): void;
-  drawImage(
-    image: CanvasImageSource | VideoFrame,
-    sx: number,
-    sy: number,
-    sw: number,
-    sh: number,
-    dx: number,
-    dy: number,
-    dw: number,
-    dh: number,
-  ): void;
-}
-
-declare class ImageDecoder {
-  static isTypeSupported(type: string): Promise<boolean>;
-  constructor(desc: ImageDecoderInit);
-  decode(opts?: Partial<ImageDecodeOptions>): Promise<ImageDecodeResult>;
-}