Which document formats can be checked?

Word documents (.docx) and plain text (.txt, .md) are opened by Syft's document reader and their text is analysed by Syft Detect. A PDF is read for its metadata only: Syft does not extract text from PDFs yet, so a PDF's writing cannot be checked on this page.

How long a document can it read?

Long ones: the whole extracted text is read and scored sentence by sentence. It needs at least about 80 words to estimate anything; below that it reports insufficient signal.

Does it check the document's metadata as well?

This page checks the writing. The Syft workspace also reads what the file records about itself, grades what that exposes, and can produce a clean copy. The PDF metadata viewer reads a PDF's fields on its own page.

Can the result prove a document was written by AI?

The result tells you how strongly the writing carries AI-like patterns and marks the passages behind it, so you can read the evidence yourself. It is statistical evidence about writing, not proof of authorship.

AI Detector for Word Documents

Check a Word document (.docx) for signs of AI-generated writing, with the passages behind the result. Drop the file, or paste the text instead. PDFs are read for metadata only.

Published 28 September 2026Syft

Drop a Word document here

.docx is opened on this page and its text is checked below. .txt and .md are read as text. A PDF is read for metadata only: PDF text extraction is not available yet.

Choose a file

Your text, or paste instead

0 words · 0 characters

Free analysis. A free account is needed to view and save the result. Your text is encrypted while it waits and is deleted if you don’t open it.

Syft AI

Ready when you are.

Paste at least 120 words for a meaningful estimate.

The same Syft AI analysis, on every plan
Passage-level evidence, not just a number
Free account to view and keep the result

What happens to the file

Read as a document, checked as writing.

A .docx is a package. Syft opens it, reads the document body, and runs Syft Detect over the text passage by passage.

Whole-document reading

The extracted body is read from the first paragraph to the last and every sentence is scored, so a long report is read as a report, not as its first page.

Passage-level evidence

Sentences at or above the AI-like threshold are marked on the text itself, with the features that drove each one, so the result can be checked against the writing.

The file stays with you

The file is never uploaded from this page; only its extracted text goes to Syft Detect. Text needed for detection is sent once over an encrypted connection to Syft's own servers, is never used to train a model or shared with anyone, and is deleted once you open the result or it expires unopened. In the page, the text is held in memory until you clear it or leave, and it is never placed in a URL, storage or analytics.

PDFs

A PDF is read for what it records.

Drop a PDF and Syft reports the record it carries: title, author, creator application, producer and dates. Extracting a PDF's text for the writing check has not shipped, so a PDF's prose cannot be checked here, and this page says so rather than pretending.

OBSERVEDDropping a PDF on this page shows its title, author, creator application, producer and dates. The writing inside it is not analysed.

OBSERVEDTo check a PDF’s writing today, paste the text, or check the Word document it was exported from. When PDF text extraction ships, this page will read it without a change to anything else.

Open the PDF metadata viewer

In the workspace

The same document, every lens.

An account opens the document as an item: the AI map drawn on the text, the metadata the file carries, the privacy exposure it creates, Compare for drafts, and Humanize for the passages you want to revise.

File limits are the plan’s: 16 MB per file on Free, 64 MB on Pro. Those figures come from the product’s own plan definitions.

Create a free account How Syft reads AI signals

A document in the Syft workspace with the AI map on: sentences associated with AI-like evidence are highlighted directly on the text while the rest reads unmarked — The AI map, drawn on the document itself: a real capture over an essay draft.

Read it honestly

What a document check can and cannot tell you.

Questions

About checking documents.

Which document formats can be checked?: Word documents (.docx) and plain text (.txt, .md) are opened by Syft's document reader and their text is analysed by Syft Detect. A PDF is read for its metadata only: Syft does not extract text from PDFs yet, so a PDF's writing cannot be checked on this page.
Is my document uploaded?: The file itself is not. It is opened with Syft's own document reader, and only the extracted text goes to Syft Detect. Text needed for detection is sent once over an encrypted connection to Syft's own servers, is never used to train a model or shared with anyone, and is deleted once you open the result or it expires unopened.
How long a document can it read?: Long ones: the whole extracted text is read and scored sentence by sentence. It needs at least about 80 words to estimate anything; below that it reports insufficient signal.
Does it check the document's metadata as well?: This page checks the writing. The Syft workspace also reads what the file records about itself, grades what that exposes, and can produce a clean copy. The PDF metadata viewer reads a PDF's fields on its own page.
Can the result prove a document was written by AI?: The result tells you how strongly the writing carries AI-like patterns and marks the passages behind it, so you can read the evidence yourself. It is statistical evidence about writing, not proof of authorship.