📄 PDF 摘要（抽取式）Summarize PDF (Extractive)
从 PDF 抽取文本，按词频选出 1–30 个关键句做本地摘要（非生成式 AI）；加密的 PDF 输入打开密码即可。本地处理。Extract PDF text and pick the top 1–30 sentences by word frequency (extractive, not generative AI); for an encrypted PDF, enter its password. Processed locally.
使用说明与常见问题How-to & FAQ
「PDF 摘要（抽取式）」是什么？What is the Summarize PDF (Extractive) tool?
从 PDF 抽取文本，按词频选出 1–30 个关键句做本地摘要（非生成式 AI）；加密的 PDF 输入打开密码即可。本地处理。Extract PDF text and pick the top 1–30 sentences by word frequency (extractive, not generative AI); for an encrypted PDF, enter its password. Processed locally.
如何使用「PDF 摘要（抽取式）」？How do I use the Summarize PDF (Extractive) tool?
在「PDF 摘要（抽取式）」中，选择或拖入文件，按需设置「句子数」等选项，然后点击「生成摘要」按钮即可。加密的 PDF 会提示输入密码（出现「打开密码」栏和「打开」按钮），输入密码并点「打开」后再继续。In the Summarize PDF (Extractive): Choose or drop your files, set "Sentences", then click "Summarize". For an encrypted PDF, the page asks for its password (a Password field and an Open button appear) — enter it, click Open, then continue.
加密的 PDF 可以吗？Can it read a password-protected PDF?
可以。选择加密的 PDF 后会出现「打开密码」栏，输入密码并点「打开」（或按 Enter）即可生成摘要；密码只在本地使用。Yes. When you choose an encrypted PDF a Password field appears; enter the password and click Open (or press Enter) to make the summary. The password is only used locally.
句子数可以填多少？How many sentences can I ask for?
1–30 的整数，默认 5；超出范围、空着或填小数会提示错误而不会悄悄改值。A whole number from 1 to 30 (default 5); an out-of-range, empty or decimal value shows an error instead of being changed silently.
是 AI 吗？Is this AI?
不是。按词频给句子打分再选出靠前句子，适合快速浏览，不是模型生成。No. Sentences are scored by word frequency — good for skimming, not model-generated.
扫描件？Scans?
纯图像 PDF 几乎提不出文字，请先 OCR。Image-only PDFs yield little text; OCR first.
有哪些选项可以调整？What options can I adjust?
「PDF 摘要（抽取式）」的设置：「打开密码」可留空；「句子数」默认 5，范围 1–30；可选文件：PDF。每次生成结果都按当前设置处理。Settings in the Summarize PDF (Extractive) — "Password" optional; "Sentences" default 5, range 1–30; files: PDF. The result always uses the current settings.
「PDF 摘要（抽取式）」免费吗？需要注册吗？Is the Summarize PDF (Extractive) free? Do I need an account?
「PDF 摘要（抽取式）」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Summarize PDF (Extractive) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.