Supported File Types
3 min read
Nutshell AI summarises the formats below. Files outside this list are still archived by Squirrel; they just do not receive a Nutshell summary. Per-extension processing can be toggled on or off from the File Processing & Security page in the Squirrel admin portal.
Supported formats
| Category | Extensions |
|---|---|
.pdf | |
| Word | .docx, .dotx, .dotm |
| Excel | .xlsx, .xlsm, .xltx, .xltm |
| PowerPoint | .pptx, .pptm, .potx, .potm, .ppsx, .ppsm |
| Plain text | .txt, .text |
| Legacy Office | .doc, .xls, .ppt, .csv, .rtf |
Modern formats (the Open XML .*x / .*m family) are the fastest to process — Nutshell reads their text directly. Legacy Office formats (.doc, .xls, .ppt, .csv, .rtf) are fully supported but slower because they require an additional parsing step before summarisation.
How each file type is read
- Word — full text body. Fastest and most accurate to summarise.
- Excel — sheet and tab names, headers, comments, and cell text. Nutshell summarises trends and context, not raw formulas.
- PowerPoint — visible text on slides, slide titles, and speaker notes. The summary captures the flow and themes of the deck.
- PDF — text content. Image-only or scanned PDFs without an embedded OCR layer will produce thin summaries because there is no text to read.
- Text and legacy Office — straightforward reads. Legacy formats add conversion overhead but produce the same quality of summary as their modern equivalents.
Files outside the supported list
Files that are not in the supported list — images, video, audio, executables, custom binary formats — are still archived by Squirrel and can still be restored on demand. They just do not get a summary written back to their SharePoint stub. Search and Copilot fall back to filename and site metadata for those, which is the same behaviour you get without Nutshell.
If a file type your organisation relies on is not on the list, contact sales@smikar.com — the format catalog is extended based on customer demand.
Toggling per-extension processing
The File Processing & Security page shows every supported extension with a per-extension toggle. Turning an extension off tells Nutshell to skip files with that extension — useful when a particular format in your tenant is high-volume and low-signal (for example, some organisations skip .csv because summaries of raw data extracts add limited value).
Toggling an extension does not affect Squirrel's archive behaviour — files with that extension continue to archive normally. Only summarisation is skipped.
See also
- Summarisation modes — coverage settings that interact with file size and type.
- How Nutshell works — where the extraction step reads each format.
- Redaction — how sensitive fields are stripped before the summary is written.
Need help? support@smikar.com.