diff --git a/compositor_web/src/wasm/input_uploader.rs b/compositor_web/src/wasm/input_uploader.rs
index d92f75eff..a928bd4d5 100644
--- a/compositor_web/src/wasm/input_uploader.rs
+++ b/compositor_web/src/wasm/input_uploader.rs
@@ -4,7 +4,6 @@ use compositor_render::{Frame, FrameData, FrameSet, InputId};
 use wasm_bindgen::JsValue;
 
 use super::types;
-use super::wgpu::pad_to_256;
 
 #[derive(Default)]
 pub struct InputUploader {
@@ -73,7 +72,7 @@ impl InputUploader {
                     &frame.data,
                     wgpu::ImageDataLayout {
                         offset: 0,
-                        bytes_per_row: Some(pad_to_256(4 * size.width)),
+                        bytes_per_row: Some(4 * size.width),
                         rows_per_image: Some(size.height),
                     },
                     size,
diff --git a/compositor_web/src/wasm/output_downloader.rs b/compositor_web/src/wasm/output_downloader.rs
index dd9e5cbd7..8da3671a8 100644
--- a/compositor_web/src/wasm/output_downloader.rs
+++ b/compositor_web/src/wasm/output_downloader.rs
@@ -84,26 +84,32 @@ impl OutputDownloader {
             FrameData::Rgba8UnormWgpuTexture(_) => types::FrameFormat::RgbaBytes,
             _ => return Err(JsValue::from_str("Unsupported output frame format")),
         };
+        let mut data: Vec<u8> = Vec::with_capacity(4 * resolution.width * resolution.height);
+        for chunk in buffer_view.chunks(pad_to_256(4 * resolution.width as u32) as usize) {
+            data.extend(&chunk[..(4 * frame.resolution.width)]);
+        }
 
         let frame = Object::new();
         frame.set("resolution", serde_wasm_bindgen::to_value(&resolution)?)?;
         frame.set("format", serde_wasm_bindgen::to_value(&format)?)?;
-        frame.set("data", wasm_bindgen::Clamped(buffer_view.to_vec()))?;
+        frame.set("data", wasm_bindgen::Clamped(data))?;
 
         return Ok(frame);
     }
 
     fn create_buffer(device: &wgpu::Device, resolution: Resolution) -> wgpu::Buffer {
+        let size = pad_to_256(4 * resolution.width as u32) * resolution.height as u32;
         device.create_buffer(&wgpu::BufferDescriptor {
             label: None,
-            size: (4 * resolution.width * resolution.height) as u64,
+            size: size as u64,
             usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
             mapped_at_creation: false,
         })
     }
 
     fn ensure_buffer(buffer: &mut wgpu::Buffer, device: &wgpu::Device, resolution: Resolution) {
-        if buffer.size() != (4 * resolution.width * resolution.height) as u64 {
+        let size = pad_to_256(4 * resolution.width as u32) * resolution.height as u32;
+        if buffer.size() != size as u64 {
             *buffer = Self::create_buffer(device, resolution);
         }
     }