BlockSync
Export block attributes to Excel, edit, and write them back safely.
AutoCAD 2021–2027 · English / 日本語 / 简体中文
12 drawings scanned, 2 block definitions found — Files, block list and export in one screen.
The problem
DATAEXTRACTION only goes one way, and ATTOUT/ATTIN only handles one drawing at a time.
How BlockSync works
These are the tabs inside the actual app, in the order they appear — every screenshot below is a real, unedited capture of BlockSync running.
Step 1 — Extract every attribute to one Excel file
Add DWG files, tell BlockSync which blocks matter, and get a single workbook with one row per attribute instance across the whole batch.
- 1Add Files… or Add Folder… — mix and match any number of DWGs from anywhere on disk into one batch.
- 2BlockSync scans every file for block definitions, layers, and paper-space viewports, with a live per-file progress bar.
- 3In the Blocks tab, check the block(s) you actually want. Each row already shows its reference count, how many of your files contain it, whether it's a dynamic block, and whether it has attributes at all — so you're not guessing before you commit to an export.
- 4Search by name, or use Select All / Select None / Invert to manage the checklist on a big project with dozens of block types.
- 5Need a narrower export? Switch to the Layers or Viewports tab and check specific layers or paper-space viewports — only blocks placed on/visible through the checked ones are extracted. Leave nothing checked to extract everything, as usual.
- 6Open Options to include nested blocks (references inside other blocks, not just top-level inserts), dynamic block attributes (visibility states, custom parameters), geometry (position + rotation), and layer info — each as its own column. Turn on Parallel processing to scan and extract multiple files at once on a fast machine.
- 7Click Extract to Excel. A timestamped .xlsx appears in the output folder shown on screen (defaults to the shared folder of your DWGs, or a fixed default if they're scattered across several) — Open Output Folder jumps straight there.
Options on this screen
- Include nested blocks
- Also extract block references nested inside other blocks, not just top-level ones.
- Include dynamic block attributes
- Extract dynamic block properties (e.g. visibility states, custom parameters) alongside regular attributes.
- Include geometry
- Extract each block reference's position and rotation as extra columns.
- Include layer info
- Extract the layer each block reference is placed on.
- Parallel processing
- Process multiple DWG files at once instead of one at a time. Faster, but uses more memory.
Step 2 — Preview the exact diff, then write back
Edit the exported sheet in Excel however you like — BlockSync matches every row back to its exact attribute instance and shows you precisely what will change before touching a single drawing.
- 1Pick the Excel workbook you exported and edited (Step 1), and the DWG folder to match it against — this defaults to the Excel file's own folder, and matches purely by exact filename, so moving the workbook around doesn't confuse it.
- 2Choose a backup folder, or leave Automatic backup on — every file that's about to be written gets copied there, unmodified, before anything changes.
- 3BlockSync reads the workbook and matches every row back to the exact block instance it came from (by file + object handle, not just row order). Anything in Excel with no matching DWG in the folder shows up under the Unmatched tab instead of silently failing or crashing the run.
- 4The Diff preview tab lists every file with a Changed count and a Blocked count. Select a file to see the full attribute-by-attribute table: File, Handle, Block, Attribute, Current value, and New value, side by side. Rows with no change are hidden by default — tick Show unchanged rows if you want to audit everything anyway.
- 5Check off exactly the files you want to include, then Write Selected Files. A confirmation dialog spells out exactly how many files and how many attribute changes are about to happen — no surprises.
- 6After writing, BlockSync reads every changed attribute straight back out of the drawing to verify it matches what was intended. Any mismatch is called out by name in the write results report rather than assumed to have worked.
- 7Rollback All restores every file touched in that run from its pre-write backup in a single click — no manually hunting down which files changed.
Options on this screen
- Automatic backup
- Each written file is copied, unmodified, into the backup folder before any change is made. Turn this off only if you don't need to roll back.
- Show unchanged rows
- By default the diff view hides attributes with no change, so a 2,000-row batch doesn't bury the dozen edits that matter.
Also included
Selection profiles
Save the exact set of checked blocks as a named profile (Save Profile…) and reload it later (Load Profile) — useful when the same handful of block types get exported on a recurring basis across different projects.
Read-back verification, not blind trust
Every write-back re-reads the attribute it just wrote from the drawing and compares it to what was intended. If AutoCAD silently rejected or altered a value, BlockSync tells you which file and which attribute — it doesn't just assume success.
Dynamic blocks and nested attributes handled correctly
Dynamic blocks report their effective attribute set per visibility state instead of a flattened, misleading list, and attributes nested inside block references (not just top-level inserts) are picked up — a class of block that AutoCAD's own DATAEXTRACTION wizard frequently misses or duplicates.
Free-edition version metadata, always visible
Every export stamps a SpecVersion, export timestamp, BlockSync version, AutoCAD version used, and Edition (Free/Pro) into the workbook, plus a SHA-1 per source file — so a sheet handed to a colleague is traceable back to exactly how and when it was produced.
Environment & requirements
Everything that determines whether BlockSync will run on your machine, and how it behaves once it does.
- No Microsoft Excel installation required — BlockSync reads and writes .xlsx directly with its own engine (ClosedXML), so it works on a machine that has AutoCAD but not Office.
- Windows 10/11, 64-bit only.
- Requires a licensed, full version of AutoCAD (2021–2027). AutoCAD LT is not supported — LT can't run the background automation BlockSync depends on.
- If more than one AutoCAD version is installed, pick which one to use under Settings → AutoCAD, or leave it on "Auto (newest installed)" — if that version fails to load for any reason, it falls back to another installed version automatically.
- Built on .NET 8. If the .NET 8 Desktop Runtime isn't already on your machine, the installer prompts to fetch it from Microsoft (free, one-time, roughly 60 MB).
- Network access is used only to check your license at startup and periodically afterward. Scanning, reading and writing all happen locally through AutoCAD's own engine — no drawing content is ever uploaded.
- Interface language: English / 日本語 / 简体中文.
- Batches of many files can process several drawings in the background in parallel — tune "Max parallel AutoCAD instances" in Settings to trade speed for CPU/memory headroom.
- Every long-running action shows a progress bar with a percentage and estimated time remaining, and can be canceled mid-run.
- Settings → Diagnostics → Open Log Folder gets you straight to the host and plugin logs if something needs troubleshooting.
See also the site-wide system requirements page comparing all tools.
Scenarios
A few of the situations BlockSync is built for — if yours isn't listed, it's probably still covered by one of the tabs above.
QA before delivery
Before
Opening 200 drawings one by one to check title block data before a submission deadline.
After
Extract all attributes to one sheet, scan for mismatches, fix in bulk, write back.
Time saved
~6 hours → 20 minutes
Bulk title block correction
Before
A company address, client name, or project phase changes mid-project, and every sheet's title block still shows the old value — fixing it means opening each drawing, double-clicking the attribute, retyping, and saving.
After
Export the TITLE/CLIENT/ADDRESS attributes across the whole set, find-and-replace the old value in Excel, write back with a diff preview confirming exactly which sheets change and to what.
Time saved
~5 hours → 15 minutes
Valve / equipment tag renumbering
Before
A P&ID revision renumbers valve and instrument tags (e.g. V-101 → V-201 across a unit), and every drawing referencing the old tag in a block attribute needs updating consistently — miss one and the tag list no longer matches the field.
After
Export every TAG attribute to Excel, apply the old-tag-to-new-tag mapping as a lookup formula or find-and-replace, write back — the diff preview shows every single tag change before anything is committed, so a mapping mistake is caught before it reaches a drawing.
Time saved
~4 hours → 20 minutes for a 150-drawing unit
Vendor part number update across a BOM
Before
A component's manufacturer part number changes (a valve model gets discontinued, a replacement is qualified), and the old part number is baked into a block attribute on every drawing that uses that component.
After
Filter the export to just that block's PART_NO attribute, replace the old value, write back to every affected drawing in one pass instead of hunting through a project file by file.
Time saved
~3 hours → 10 minutes
Post-acquisition rebranding
Before
After a merger, every drawing's title block still carries the old company name and logo block reference, and legal wants it fixed everywhere before the next submission — but nobody wants to open 500 drawings one at a time.
After
Export the COMPANY attribute project-wide, replace it, write back with automatic backup — 500 drawings updated in one run instead of a week of manual edits.
Time saved
Multi-day manual effort → under an hour
What early testers are saying
BlockSync hasn't had a public release yet, so there's no customer roster to quote — these are real notes from early testers, attributed by role rather than name.
“Pulling together a purchase list from a handful of drawings by hand is fine. Try that across 200, and it just stops being something a person can do accurately.”
“Retitling every drawing after a revision meant opening each one, finding the field, retyping it, saving, next file. Slow and honestly miserable.”
“This tool saved me during a crunch week. I would not want to redo that project's title blocks by hand again.”