> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bedrock.cv/llms.txt
> Use this file to discover all available pages before exploring further.

# Compare drawings

> Compare all matching sheets between two drawing revisions.

Compare all matching sheets between two drawing revisions. Sheets are matched by sheet number, and overlays are created for each matched pair.

## What Happens Next

1. Sheets are matched by sheet number (e.g., A-101 in both drawings)
2. For each matched sheet pair, blocks are compared
3. [Overlays](/cms-api/resources/overlays) are created for each block comparison
4. The job completes when all comparisons finish

Poll [`GET /jobs/{id}`](/cms-api/jobs/get) to track progress. Once complete, use [`GET /overlays?job_id={id}`](/cms-api/overlays/list) to retrieve the results.

## Sheet Matching

Sheets are matched by their `sheet_number` field:

| Source Sheet | Target Sheet | Result   |
| ------------ | ------------ | -------- |
| A-101        | A-101        | Compared |
| A-102        | A-102        | Compared |
| A-103        | (missing)    | Skipped  |
| (missing)    | A-104        | Skipped  |

To compare sheets with different numbers, use [Compare Sheets](/cms-api/overlays/compare-sheets) instead.