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Flatten PDF

Merge all layers and elements of a PDF into a single layer in seconds. It’s fast and free to flatten PDFs for enhanced document integrity, reduced file sizes, and easier sharing on any system.

  • Works on Mac, Windows, and Linux devices
  • Free to use without downloading any software
  • Trusted by 2.4 billion people since 2013

Best Online Tool to Flatten PDFs

Our Flatten PDF tool lets you quickly merge all elements of a PDF into a single layer. Turn complex interactive documents into simple, secure PDFs for perfect printing and sharing.

Prevent Data Tampering

Flattening a PDF permanently embeds all content into the document—from text and images, to annotations and form fields. This prevents information tampering and maintains document integrity.

Perfect Printing Every Time

With flattened PDFs, you know that even the most complex PDF layouts print like you see them on screen. Even multiple overlays like forms and graphics print with perfection.

Accessible Documents on Any System

PDFs are universally shareable and viewable. But some systems struggle with complex multi-layered documents. When you flatten a PDF, these compatibility issues disappear.

How To Flatten PDFs for Free

  1. Import or drag & drop your file to our Flatten PDF tool.
  2. Edit the PDF with our other tools if needed.
  3. Download or share your flattened PDF when ready—done!

Flatten Any PDF for Accuracy & Integrity

  • Reduce File Sizes

    A PDF with multiple layers and elements takes up more space. When you flatten a PDF, you also smash your document size into files that are easier to share and store.

  • Flatten PDFs Online on Any Device

    Our Flatten PDF tool can be used from any device right through your browser. Try it out—just drag your PDF into the box above, no matter what screen you’re using.

  • Edit Before You Flatten PDFs

    Need to annotate a PDF before you permanently flatten it? Start with our PDF Editor to get just what you need, then flatten your PDF to preserve your document integrity.

  • Increase Your PDF Security

    A PDF with multiple layers adds multiple elements that can be tampered with. When you flatten a PDF you basically lock in the content, increasing the security and integrity of your documents.

  • All Platforms Love Flattened PDFs

    A flatter document is an accessible document. No matter the platform or system, by flattening a PDF you’re reducing compatibility issues that come with complex docs.

  • Stay Private With Secure Encryption

    Your documents are secured with state-of-the-art TLS encryption technology the whole way. Upload, flatten your PDF, and download your new doc—no one will see your files but you.

FAQs About Our Flatten PDF Tool

  • What is Flatten PDF?

    "Flattening" a PDF is the process of merging all layers and elements of a document into a single layer. It’s kind of like taking an unbaked pizza stacked with layers of ingredients, and baking it so it all holds together for easy sharing and consumption. With a PDF, it helps your doc’s contents from being modified or manipulated, and improves the fidelity and accuracy of your PDF.


  • Why is it important to flatten PDF layers?

    By merging PDF layers, you’re making your document more secure, more reliable, and more compatible across any system. It also removes complexity from the doc, which reduces file size and makes it more shareable across systems. And with everything locked in place, your PDF looks the same no matter who opens it or what device they're using. And when you go to print your PDF, it comes out exactly like it looks on your screen. No surprises!


  • What happens when I flatten a PDF?

    Once a PDF is flattened, the text, images, form fields, and other elements are merged into a single layer. This means these elements can no longer be edited separately, which essentially locks in your PDF’s appearance. Other interactive elements like form fields and URL hyperlinks are also removed. So you’re left with a static document that can be easily shared, accessed, and printed on any system with a consistent appearance.


  • Can I undo a flattened PDF to restore the layers?

    In general, no. Once a PDF has been flattened, the process can’t be easily reversed. So make sure you save a copy of your PDF before flattening in case you need to make edits later. Of course, you can also use a separate tool like our free PDF Editor to recreate annotations, images, links, and more if you don’t have an unflattened version of your doc.


  • How can I flatten PDFs online for free?

    With the Smallpdf Flatten PDF tool, you can easily merge PDFs with multiple layers into a single-layer document. It’s a cloud-based tool that you can access from any device or browser. And it’s completely free to flatten PDFs with no sign-up required. Just scroll to the top of this page, and drop your doc in the box.


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