🩹 PDF 修复（打不开的 PDF 恢复）Repair PDF
修复损坏或打不开的 PDF：重建交叉引用表和文件结构，去掉文件头前的多余数据，跳过读不出的坏页，尽量恢复下载不完整的文件；结构无法恢复时可按页面图像重建。先保留文字和画质，修复结果显示恢复了几页、用的什么方式，全程本地完成。Fix a damaged PDF that will not open — the cross-reference table and file structure are rebuilt, stray bytes before the header removed, unreadable pages skipped, and partly downloaded files recovered as far as possible. If the structure cannot be saved, pages can be rebuilt from rendered images. Text and quality are preserved whenever possible, and the result tells you how many pages were recovered and how. Fully local.
使用说明与常见问题How-to & FAQ
「PDF 修复（打不开的 PDF 恢复）」是什么？What is the Repair PDF tool?
修复损坏或打不开的 PDF：重建交叉引用表和文件结构，去掉文件头前的多余数据，跳过读不出的坏页，尽量恢复下载不完整的文件；结构无法恢复时可按页面图像重建。先保留文字和画质，修复结果显示恢复了几页、用的什么方式，全程本地完成。Fix a damaged PDF that will not open — the cross-reference table and file structure are rebuilt, stray bytes before the header removed, unreadable pages skipped, and partly downloaded files recovered as far as possible. If the structure cannot be saved, pages can be rebuilt from rendered images. Text and quality are preserved whenever possible, and the result tells you how many pages were recovered and how. Fully local.
如何使用「PDF 修复（打不开的 PDF 恢复）」？How do I use the Repair PDF tool?
在「PDF 修复（打不开的 PDF 恢复）」中，按需设置「修复方式」等选项，然后点击「修复 PDF」按钮即可。支持拖放文件。Set "Method", then click "Repair PDF". Drag-and-drop files is supported.
能修复哪些问题？What problems can it fix?
常见的有：交叉引用表（xref）损坏或偏移错误、文件头前混入了多余数据、下载或传输中断导致文件结尾缺失、个别页面对象损坏。工具会扫描整个文件重新找出所有对象，按页重新组装成一个结构完整的新 PDF。Common cases: a broken or misaligned cross-reference (xref) table, stray data before the file header, a missing end from an interrupted download or transfer, and individual damaged page objects. The tool scans the whole file for objects and reassembles the pages into a new, structurally sound PDF.
三种修复方式有什么区别？How do the three methods differ?
“重建文件结构”直接复制原页面内容，文字可选中、画质不变；“按页面图像重建”先用 pdf.js 把每页画出来（150 DPI）再存为图片页，能救回结构严重损坏但还能显示的页面，代价是文字不能再选中或搜索；“自动”先试第一种，如果恢复的页数比第二种少，就改用第二种。Rebuild structure copies the original page content, so text stays selectable and quality is unchanged. Rebuild from page images draws each page with pdf.js at 150 DPI and stores it as an image page — it can rescue pages that still display but whose structure is badly broken, at the cost of text that can no longer be selected or searched. Auto tries the first and switches to the second only if that recovers more pages.
一定能修好吗？Will it always work?
不一定。如果文件只下载了一小部分，丢失部分的页面内容已经不存在，无法凭空恢复；完全不是 PDF 的文件（比如被病毒或软件覆盖）也无法修复。工具会告诉你恢复了几页、跳过了几页。No. If only part of the file was downloaded, the missing pages' content is simply gone and can't be recreated; files that are no longer PDFs at all (overwritten by other software, for example) can't be repaired either. The result tells you how many pages were recovered and how many were skipped.
加密的 PDF 可以修复吗？Can encrypted PDFs be repaired?
不能直接修复。请先用“PDF 解密”工具输入密码去掉加密，再用本工具修复。Not directly. Remove the encryption with Unlock PDF (you'll need the password) first, then repair the result here.
文件会上传吗？Is my file uploaded?
不会。修复用 pdf-lib 和 pdf.js 在浏览器里完成，文件不会离开你的设备。No. Repair runs in your browser with pdf-lib and pdf.js; the file never leaves your device.
「PDF 修复（打不开的 PDF 恢复）」免费吗？需要注册吗？Is the Repair PDF free? Do I need an account?
「PDF 修复（打不开的 PDF 恢复）」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 Repair PDF is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.