You've got a contract to sign. You could print it, sign it with a pen, scan it, and email it back — or place a signature onto the PDF directly on your computer. Before doing that for anything that matters, it's worth knowing exactly what kind of "signature" you're creating, because the term covers several genuinely different things with different levels of legal weight.
并非所有 PDF 签名都相同
- Drawn signature: You draw your signature with a mouse, trackpad, or finger, and it's placed as an image on the page.
- Typed signature: You type your name and it's rendered in a handwriting-style font, then placed on the page.
- Uploaded signature image: A photo or scan of your actual physical signature, placed on the page as an image.
- Certificate-based digital signature: A cryptographic signature tied to a verified digital certificate, which mathematically binds the signature to the exact document and can detect if the file is altered afterward. This is a different technology entirely from the three above.
The first three are all, technically, "electronic signatures" — a mark applied with the intent to sign. None of them cryptographically verify who actually signed or whether the document was altered afterward. A certificate-based digital signature does both of those things, which is why it carries more weight for high-stakes documents.
PDFly 的 PDF 签名工具会生成什么
PDFly's 签署 PDF tool places a drawn, typed, or uploaded signature image onto the page — it's a visual signature, not a certificate-based digital signature with cryptographic verification. It doesn't verify your identity; it simply places whatever signature you provide onto the document, positioned wherever you click.
如何签署 PDF
- Open PDFly's 签署 PDF tool.
- 上传 PDF 文件。
- 通过手绘、输入姓名或上传图片来创建签名。
- 点击页面上要放置签名的位置。
- 下载已签署的 PDF，并保存一份副本以备记录。
这种方式制作的签名具有法律效力吗？
It depends — on your jurisdiction, the type of document, and what the other party or a governing authority requires, and that's not something this article or PDFly can determine for you. This isn't legal advice, but here's the general shape of it: many places have laws recognizing electronic signatures as generally valid for most everyday agreements, provided there's clear intent to sign. But some categories of documents — certain contracts, court filings, notarized paperwork, government forms — have specific requirements that a simple drawn or typed signature may not satisfy, and some counterparties specifically require a certificate-based digital signature with an audit trail from a dedicated e-signature service.
The practical takeaway: for routine internal approvals, low-stakes forms, and everyday agreements, a drawn or typed signature is often perfectly fine. For anything with real legal or financial weight, or where the other party has specific requirements, confirm what's actually required before you rely on a visual signature — with the counterparty, or with a lawyer if it matters enough to ask one.
常见问题
Is a drawn or typed signature legally valid?
这取决于所在司法管辖区和文件类型。PDFly 提供电子签名工具，但不对法律合规性作出认证。普通文件通常可以使用；对于重要或受监管的文件，应先确认具体要求。
Is this the same as a certificate-based digital signature?
不是。PDFly 的工具是在页面上放置可见的签名图片。基于证书的数字签名则是一种独立的加密技术，可验证签署者身份，并检测文档之后是否被篡改。
Can I sign a PDF on my phone?
可以——只要设备上有浏览器，通常就能使用基于浏览器的工具。
Can I save my signature for future use?
有些工具支持保存签名；否则，你可以每次重新创建签名。