透かし挿入
無料·登録不要·ファイルは端末の外に出ません
How to watermark a PDF in 3 steps
Mark documents as DRAFT, CONFIDENTIAL, or your own name — visible enough to matter, subtle enough not to obscure.
Upload the PDF
Drop the document in the box above. It stays on your device throughout.
Design the watermark
Type your text, set opacity and rotation, pick a position or tile it across the page.
Download the marked copy
Click Add watermark. Every page carries your stamp, and the file downloads instantly.
Why watermark PDFs with AmiPDF
Professional stamping, CJK included — where most free tools break.
設計からプライベート
処理はすべてブラウザ内で完結。アップロード・保存・共有は一切ありません。
登録不要・透かしなし
アカウント不要、メール不要、制限なし。出力は入力とまったく同じ。
Full CJK support
Chinese, Japanese, and Korean watermark text renders perfectly — a common failure point in free tools, solved by design here.
どの端末でも動作
Windows、Mac、Linux、Android、iOSで同じ速さ — インストール不要。
When to watermark PDF pages
Review copies marked DRAFT before they circulate, contracts stamped CONFIDENTIAL, portfolios signed with the owner's name, training materials labeled INTERNAL. A watermark states status at a glance and discourages casual reuse.
Watermarking happens locally — private documents stay private.
Add PDF watermarks on any platform
AmiPDFはブラウザで動作 — インストールも設定も更新も不要。
Windows
Chrome, Edge, Firefox
macOS
Safari, Chrome
Linux
Any modern browser
iOS
Safari on iPhone, iPad
Android
Chrome, Samsung Internet
Frequently asked questions
Can I watermark with Chinese, Japanese, or Korean text?
Yes — full CJK support is a headline feature. Characters render correctly, including full-width punctuation.
How do I keep the watermark from hiding the content?
Lower the opacity slider until the text is present but unobtrusive. 20-30% works for most documents.
Can I place different text on different pages?
The watermark applies uniformly to the whole document. For per-page text, split the PDF first, watermark each part, then merge.
Does a watermark prevent copying?
A visible watermark deters, it doesn't prevent. For actual restrictions (copying, printing), use Protect PDF to set document permissions.
Can I add an image logo as watermark?
This tool stamps text watermarks. Image watermarking is on the roadmap.
Is the watermarked file uploaded anywhere?
No. The watermark is rendered and stamped locally in your browser.
関連するPDFツール
続けて — PDF作業に必要なすべてが、無料・ローカル実行。