ASD File Documentation
Summary
A Word AutoRecover Document (.asd) file is an automatic backup snapshot Microsoft Word saves of your open document so it can restore your work after a crash. You normally do not open it by hand: reopen Word and pick the file from the Document Recovery pane, or use File > Open > Recover Unsaved Documents. Internally it is an OLE Compound File; its MIME is application/octet-stream. Note: in Ableton Live, .asd means something entirely different (audio analysis data).
Technical details
| Feature | Value |
|---|---|
| Full name | Microsoft Word AutoRecover Document |
| File extension | .asd |
| MIME type | application/octet-stream |
| Format type | Binary auto-save snapshot of a Word document (AutoRecover) |
| Developer | Microsoft |
| Introduced | Word 97 era; still used through Microsoft 365 Word |
| Container (modern) | OLE / Compound File Binary (CFBF) |
| Magic number | D0 CF 11 E0 A1 B1 1A E1 (modern OLE snapshots; version-dependent) |
| Open standard | No — internal, undocumented Word snapshot |
| Default save interval | Every 10 minutes (configurable in Word > Options > Save) |
| Default location (Windows) | %AppData%\Microsoft\Word\ |
| Typical name | AutoRecovery save of <docname>.asd |
| Opened by | Microsoft Word (recovery pane / Open and Repair) |
| Safe to delete? | Yes, once the real document is saved and intact |
| Related extensions | .wbk, .doc, .docx, .tmp, .asv |
| Also used by | Ableton Live audio analysis file (unrelated) |
| Specification | support.microsoft.com (AutoRecover) |
What is an ASD file?
An .asd file is the AutoRecover file Microsoft Word creates automatically while you edit a document. At a set interval — by default every 10 minutes, adjustable in Word > Options > Save — Word writes a snapshot of the open document to a hidden AutoRecover location, so that if Word or Windows crashes, your unsaved changes can be restored. The format dates to the Word 97 era and is still used by current Microsoft 365 Word.
The key thing to understand is that an .asd is a safety net, not your real document. When Word reopens after a crash it shows the Document Recovery pane and offers to restore the work from the .asd; once you save the recovered file normally, Word usually deletes the .asd. You are not meant to open it directly, and opening it in another tool rarely produces clean text, because it is an internal Word snapshot rather than a finished document.
One disambiguation matters up front. The .asd extension is heavily reused, most notably by Ableton Live, where an .asd is a tiny per-sample audio-analysis file (tempo, warp, and pitch data) stored next to an audio clip. That has nothing to do with Word, will not open in Word, and deleting it only forces Ableton to re-analyse the sample. This article describes the Word AutoRecover file.
How AutoRecover writes the snapshot
AutoRecover runs on a timer inside Word. On each interval it writes the current state of every open, unsaved document to an .asd file in the AutoRecover folder, overwriting the previous snapshot for that document. The files are named descriptively, typically AutoRecovery save of <docname>.asd, so Word can match a recovered snapshot back to the document it came from. On Windows the default folder is %AppData%\Microsoft\Word\ (for example C:\Users\<you>\AppData\Roaming\Microsoft\Word\); you can see and change the path under Word > Options > Save > “AutoRecover file location”. On the Mac, the files live under ~/Library/Containers/com.microsoft.Word/Data/Library/Preferences/AutoRecovery.
Because AutoRecover is time-based, the .asd holds the document as it was at the last interval tick, not necessarily the last keystroke before a crash. That is why the recovered version can be a few minutes behind, and why shortening the interval trades a little performance for less potential loss.
Internal format: an OLE snapshot Word reads back
Internally, a modern Word .asd is an OLE / Compound File Binary container: it begins with the docfile signature D0 CF 11 E0 A1 B1 1A E1 and, like an old .doc, organises its content as named storages and streams inside that container. The snapshot holds the text and objects of the document at the moment of the auto-save, plus internal streams Word uses to reconstruct the document and a reference to the original filename so it can be matched back on recovery.
This is an internal, undocumented format meant only for Word to read back. The exact bytes vary by Word version, so the OLE header is a hint rather than a reliable identifier, and opening an .asd in a text editor shows mostly binary noise. The practical consequence is that the reliable way to open one is to let Word find and interpret it, not to parse it by hand.
Recovering a document from an ASD
The normal path needs no manual work. Reopen Word after a crash and the Document Recovery pane lists the auto-saved version; pick it, then save it as a proper document. If the pane does not appear, use File > Info > Manage Document > Recover Unsaved Documents, which opens the folder Word keeps these files in. If you must open an .asd by hand, in Word use File > Open, set the file-type filter to “All Files”, select the .asd, and use the arrow next to the Open button to choose Open and Repair, which is the most tolerant way to read a snapshot from a crash that happened mid-save.
There is no separate “convert an .asd” step. You recover the snapshot in Word, then Save As the format you actually want — DOCX, legacy DOC, PDF, RTF, or plain text. The .asd is only the recovery source; the real output is a normal Word file.
Can I delete ASD files?
Yes, once your real document is saved and opens correctly. AutoRecover files are temporary recovery copies, and Word usually deletes them itself after a clean save. Leftover .asd files in the AutoRecover folder are safe to remove, with one caveat: do not delete an .asd while it may still be your only copy of unsaved work. If Word crashed and you have not yet recovered and saved the document, the .asd could be the sole record of your recent edits, so confirm the recovered document is intact first.
Frequently asked questions
Where does Word store AutoRecover (.asd) files?
On Windows, by default in C:\Users\<you>\AppData\Roaming\Microsoft\Word\. You can view and change the path in Word > Options > Save under “AutoRecover file location”. On macOS they sit under the Word app container in ~/Library/Containers/com.microsoft.Word/Data/Library/Preferences/AutoRecovery.
Are Ableton .asd files the same thing?
No. In Ableton Live, an .asd is a small audio-analysis file stored next to a sample, holding tempo, warp, and pitch data. It has nothing to do with Word and cannot be opened in Word; deleting it just makes Ableton re-analyse the audio.
Why won’t my ASD file open or show the right text?
Because it is an internal Word snapshot, not a normal document. Open it through Word’s recovery (the Document Recovery pane or Open and Repair), not a text editor. If Word cannot read it, the AutoRecover file may be incomplete or captured mid-save during the crash.
References
- Microsoft Support — Recover files in Microsoft 365
- Microsoft Support — What is AutoRecover?
- Ableton — Working with analysis (.asd) files
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.