What are the benefits of PDF Flatten?

Perfect for Finalizing Official Documents — Flattening form-filled PDFs such as contracts and applications permanently locks in the entered values, making them tamper-proof and ready for secure storage and distribution as legally valid final documents.. Clean Up Review Comments — The annotation removal feature lets you strip all comments, highlights, and markups added during review stages, producing a clean final PDF ready for submission to clients and partners.. Complete Local Processing for Confidential Documents — All processing happens entirely within your browser, so there is no need to upload sensitive forms or confidential contracts to external servers, providing a completely secure environment with zero data leakage risk..

Yes, it is completely free to use, and no registration is required. Tool processing happens entirely in your browser, and your input content and uploaded files are not sent to a server. Our first-party improvement metrics use no cookies, visitor IDs, or session IDs and store only normalized page paths and daily counts for fixed event IDs.

PDF Flatten

Flatten PDF form fields and annotations into static content

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PDFフラット化

ファイルをドラッグ＆ドロップ

About PDF Flatten

【What is PDF Flatten?】 The 'PDF Flatten' tool is a free online PDF utility that merges interactive form fields (text boxes, checkboxes, dropdown lists, etc.) and annotations (comments, highlights, markups, etc.) into the static page content of your PDF, making them permanent and non-editable.

【Benefits of Flattening】 When form fields are flattened, the entered values are preserved visually but can no longer be modified or edited. This is particularly useful for finalizing official documents such as contracts and application forms, or for distributing and archiving completed forms in a tamper-proof state. The annotation removal feature also allows you to create clean PDFs by stripping all review comments, highlights, and markup annotations.

【Simple and Intuitive Operation】 The operation is straightforward: simply drag and drop your PDF file into the upload area, select your desired flattening options (flatten form fields, remove annotations), and click the process button. After processing completes, file size reduction percentages and processing statistics are automatically displayed, so you can see the results instantly.

【Complete Local Processing for Maximum Security】 The most significant advantage of this tool is that all PDF processing is performed entirely within your browser's local environment. Your PDF file is never uploaded to any external server, ensuring that confidential contracts, personal information forms, and sensitive business documents can be safely processed with absolutely zero risk of data leakage.

How to use PDF Flatten

Drag and drop the PDF file you want to flatten into the upload area.
Select your options: 'Flatten form fields' makes form values permanent, 'Remove annotations' strips all comments and markups.
Click the 'Flatten' button and check the downloaded PDF file after processing completes.

Benefits of PDF Flatten

Perfect for Finalizing Official Documents — Flattening form-filled PDFs such as contracts and applications permanently locks in the entered values, making them tamper-proof and ready for secure storage and distribution as legally valid final documents.
Clean Up Review Comments — The annotation removal feature lets you strip all comments, highlights, and markups added during review stages, producing a clean final PDF ready for submission to clients and partners.
Complete Local Processing for Confidential Documents — All processing happens entirely within your browser, so there is no need to upload sensitive forms or confidential contracts to external servers, providing a completely secure environment with zero data leakage risk.