Flatten PDF — Lock Annotations and Layers
Bake annotations, markups, and form values permanently into the page so they can't be removed or edited. The tool converts every page to an image, locking everything visible into a single flat layer. Free, in-browser, and no signup — your file stays on your device.
Free • No signup • Secure
How to use flatten pdf — lock annotations and layers
Open your PDF
Drag and drop your PDF onto the upload area, or click to choose a file. The file stays on your device — there is no server upload.
Flatten every page
USA Sky PDF renders each page in your browser, captures it as a JPEG, and re-embeds it in a fresh PDF. Annotations, highlights, comments, drawn shapes, and filled form values are all baked into the resulting image — they become part of the page itself.
Download the flattened PDF
Click Download to save the flat .pdf to your device. Recipients can view it normally, but the markup layer can no longer be peeled off or edited.
Why use USA Sky PDF
Your file stays on your device
Nothing is uploaded. The flatten runs entirely in your browser, and the new file is saved straight to your downloads folder.
Annotations baked permanently into pages
Highlights, sticky notes, drawn shapes, comments, and any filled form values all become part of the page image. A recipient can't open the file in Acrobat and delete your markups — they're not separate objects anymore.
Lossless visual fidelity
Pages are rendered at 2× the source resolution before being saved as JPEG (quality 0.85). On-screen and on paper, the flattened pages look visually identical to the source.
Free with no signup
No account, no email, no watermarks. There's nothing to upgrade for this tool because nothing leaves your device.
Frequently asked questions
Is flattening really free?
Yes. Free with no signup and no per-conversion limit.
Does the file leave my computer?
No. Flattening runs entirely in your browser. USA Sky PDF's servers never see your PDF for this tool.
Will my text still be selectable after flattening?
No. To bake every visible layer in permanently, the tool rasterizes every page — it re-renders each page to an image (JPEG) and re-wraps it in a PDF. The result looks identical, but text is now part of the image rather than selectable characters. This is the inherent trade-off of any real flatten: what makes annotations un-removable also makes the underlying text un-selectable.
Will my form fields still work?
No — they're destroyed. AcroForm widgets are interactive layers; once a page becomes an image, those interactive layers are gone and the form is baked into the picture. If recipients still need to fill in fields, don't flatten until after they've filled the form.
Will the file get smaller?
Usually not — and often it gets larger. Vector text in a typical PDF compresses much smaller than the same text rendered as a JPEG. Flatten is for locking the visible layer in place, not for shrinkage. If you need a smaller file, use the Compress tool after flattening.
What if I just want to merge filled form values without losing selectable text?
That's a different operation — sometimes called "form-field flatten" or "flatten form fields" — where the field values become non-editable text but the surrounding document text stays selectable. We don't currently offer that as a separate tool. Adobe Acrobat Pro's "Flatten Form Fields" command does this. Our Flatten tool does full-page image conversion, which is the version most users searching "flatten PDF" are looking for (lock annotations, prevent edits).