How does the summary get made?

By default it is extractive: sentences are ranked by how central they are to the document (a TextRank graph) and the top ones are kept in order. That means every sentence in the summary is verbatim from your source — it cannot invent a fact or a claim.

Can it summarize a PDF or Word file?

Yes — open a PDF, .docx, Markdown, RTF or text file and it is read inside your tab. A scanned PDF has no text layer, and the tool tells you to OCR it first rather than returning an empty summary.

What does the Chrome on-device AI option add?

In browsers that ship a built-in summarizer, it can rewrite the summary abstractively instead of selecting sentences. It still runs on your device. The output always says which engine produced it.

Is there a length limit?

No account limits apply. Very long documents just take a moment longer to rank.

Summarize Text Online — Free, No Signup, Private

Paste any text and get a key-points, TL;DR or headline summary instantly. Extractive by default, so the summary is built from your own sentences and nothing is invented.