Power Automate flows get large fast. Once a flow spills past the viewport, taking screenshots becomes a painful sequence of manual scrolling, partial captures, and trying to stitch everything together by hand.
PA Flow Capture solves that with a Firefox extension that captures the entire flow canvas and exports a single stitched PNG.
The extension detects the flow designer canvas, then lets you place two anchors with Ctrl + click to define the exact capture bounds. From there it moves the viewport tile-by-tile, pauses for settle timing, and captures each frame.
Raw captures almost always produce visible join lines because of anti-aliasing and tiny movement differences between frames. The background stitcher runs on OffscreenCanvas and uses horizontal seam matching (grayscale SAD) to line up edges and reduce visible artifacts.
// rough flow
for (const tile of tiles) {
await scrollTo(tile);
await settle();
const shot = await captureVisibleTab();
frames.push(cropToViewport(shot));
}
const finalImage = stitchWithSeamMatching(frames);
This is a Manifest V3 extension with a popup UI, content script for in-page capture orchestration, and background worker for image processing. No build system needed, so iteration is fast when tuning capture timing.
The biggest win was reliability, not speed: getting deterministic capture boundaries and predictable seams means the output is consistently readable even on very large flows.
Source code is available on GitHub with local run instructions through about:debugging in Firefox.