在线填写 PDF 表单——AcroForm 文本框、复选框、下拉框

上传 PDF，工具会检测出每一个表单字段——文本框、复选框、单选按钮、下拉菜单和签名字段——让您直接在浏览器中输入、点选和签名。填写完成的 PDF 会以真正的可填写 PDF 形式下载，任何审阅者都能在 Acrobat 或预览中打开。

可以。切换到自由模式，点击任意位置添加文本，将对勾和 X 印章放到复选框上，并叠加签名图片。这适用于扫描的税务表格、政府申请和从未做成可交互的可打印合同。

可以。你可以输入花体签名、用鼠标或手指手写签名，或上传扫描签名的透明 PNG。在页边空白处添加缩写签名，然后在下载时合并文档，这样收件人便无法移除签名。

可以。页面背景、字体、版式和安全设置都会保持完好。工具只会在现有结构之上添加你填写的内容，因此人力资源表格、税务申报和合同到手时看起来与原件完全一致。

Your PDF is uploaded over HTTPS to our secure server to detect and fill its form fields, then deleted automatically after processing — we never store, share, or sell it. Filling online this way saves printing and re-scanning; for documents under a strict no-upload data-residency rule, a fully offline desktop tool is the safer choice.

可以。开启「下载时合并」后，每个已填写的字段都会固化到页面中，防止收件人无意中更改内容。在必须锁定表单的最终版合同和报税材料中尤为适用。

检测到表单字段后，"输出"面板中会出现一个"输出文件名"字段，预填为"yourfile-filled.pdf"。你可以把它改成任何需要的名称——在向人力资源部门、学校或政府门户提交表单时，用来保持像"lastname-application-filled.pdf"这样统一的命名规范很有用。

Fill in every detected field first (text boxes, checkboxes, dropdowns and radio groups all appear automatically), set a clear Output filename so the recipient can identify it, and turn on Flatten only once you're done editing — flattening locks the values into the page so they can't be accidentally changed after you send it. Skip flattening if you expect to reopen and adjust the same PDF later.

The tool reads each field's actual AcroForm type from the PDF: dropdown and list fields render as a select box populated with the exact options the form author defined, and radio groups render as individual radio buttons for each option. This keeps your answers restricted to values the form actually accepts, so you can't accidentally type something the form wasn't built to hold.

PDF forms occasionally contain field kinds pdf-lib can't render an editable control for in the browser — most often digital signature fields, button/JavaScript fields, or barcode fields. Those show 'Unsupported field type' in the Fields panel and are left untouched in the output, while every text box, checkbox, dropdown, list and radio group next to it still fills and downloads normally. For those specific fields, open the filled PDF in Acrobat or Preview to complete them, or use Flatten to lock everything else first.

Yes. Flatten locks in whatever values are currently in each field — including blanks — so any field you didn't type into is baked in as empty. If a field must be answered before you flatten, fill it first; once flattened there is no way to edit that value again in this tool, so leave Flatten off if you plan to finish the rest of the form in Acrobat afterward.