旋转 PDF
把页面永久转正。
这款工具完全在你的浏览器中运行。文件从不上传，你可以在浏览器的网络标签中亲自验证这一点。 亲自验证：打开浏览器的网络标签观察。你会看到一个查询你是否还有剩余任务的小请求，只包含工具名称和一段哈希，绝不会包含文件。
这款工具的作用
Rotation in a PDF is a property of the page rather than a change to its contents, which means turning a page costs nothing in quality and almost nothing in file size. This tool writes that property permanently, so the document opens the right way up everywhere.
Use it when a scanner produced sideways pages, when a phone photo was saved into a PDF at the wrong orientation, or when a document mixes portrait text with landscape tables that came out rotated the wrong way.
工作原理
- Drop the PDF onto this page.
- Choose how far to turn: 90 degrees clockwise, 180 to flip upside-down pages, or 270 for 90 anticlockwise.
- Narrow it down if you need to - a page range, or only the portrait or only the landscape pages.
- Press Rotate.
- The download starts on its own.
Rotating in a PDF viewer and rotating here are different things. A viewer turns the page for your session and forgets; this writes the rotation into the file, so it survives sending, printing and opening on another device. That is the difference people are usually looking for when they search for how to rotate a PDF permanently.
The landscape-only and portrait-only filters exist because mixed documents are the common case. A report where the tables were scanned sideways needs only those pages turned, and picking them out by hand from a hundred pages is exactly the kind of tedium a tool should absorb.
Add rotates relative to whatever the page already has, which is what you want when different pages start at different angles. Set replaces the existing value, which is what you want when a document has inconsistent rotations and you want them all made the same.
Because nothing is re-rendered, a rotated scan keeps its original image data at full resolution and rotated text stays selectable and searchable.
常见问题
- 旋转会保存进文件里，还是只用于查看？
- 会保存进文件里。页面的旋转属性被写入磁盘，因此文档对你发送给的任何人都能正确显示，打印也正确。这与 PDF 阅读器里的旋转按钮不同，后者通常只影响你当前的视图。
- 只有部分页面是横着的，我能只修正那些吗？
- 可以，有两种方式。给出一个页面范围以只旋转那些页面，或者把筛选设为只横向或只纵向，让工具根据每页当前的显示方式为你挑出它们。
- 旋转会降低质量或增大文件吗？
- 都不会。旋转改变的是每页上的一个数字，而不是重绘任何内容，因此内容逐位完全相同，文件大小最多变化几个字节。
- 我的 PDF 阅读器仍然把它显示成横的，为什么？
- 几乎总是因为阅读器仍打开着旧版本。关闭并重新打开下载的文件。如果依然如此，可能是页面内容本身就被旋转着画在了一个正立的页面里，而这是旋转无法修正的——那种情况下向另一个方向旋转 90 度再对比。