Flatten PDF

To flatten a PDF, add it to the box above, choose what to flatten and press the button. Form fields, comments and marks are merged into the page itself, so the document looks exactly the same but can no longer be changed in a normal PDF reader. You can add up to 10 files in one go, each up to 200 MB.

This is an easy way to flatten pdf online free: there is no sign-up, no watermark and no app to install. The work is done on our server with MuPDF, a well-known open-source PDF engine, and your files are deleted right after.

A PDF can hold two kinds of content. The first is the page itself: text, pictures and lines that are part of the file. The second sits on top of the page as separate objects: form fields you can type in, comments, highlights, sticky notes, stamps and drawings. A reader app shows both together, so they look like one page, but the top layer can still be edited, moved or deleted.

The plain flatten pdf meaning is this: take everything that sits on top and make it part of the page. After flattening, a filled-in form field is just text on the page, a highlight is just a yellow shape, and a stamp is just a picture. Nothing looks different, but nobody can change the values or remove the marks with a normal PDF reader.

Flattening is a bit like photocopying a filled-in paper form. The copy shows the same answers, but the boxes are no longer separate, so the answers cannot be wiped off. The difference is that with the first three options here, the text in your PDF stays real text, so you can still select, copy and search it.

There is a stronger version as well. Everything (pages become images) turns each page into a picture. That is the most complete flatten, because layers and hidden content are merged into exactly what you see, but the text is no longer selectable.

Before you start, the tool shows a short line under each file, such as 4 pages, 12 form fields, 3 comments and marks. This count is made in your browser, before anything is sent, so you can see what will change. Links and pop-up windows are not counted as comments.

If a file shows 0 form fields and 0 comments and marks, the first three options have little to change. The PDF may already be flat, or what you want to fix may sit in layers, which only the image mode merges.

Flattening only changes the parts you choose. In the first three modes, the normal text, pictures, fonts and drawings of each page are left as they are, and the number of pages stays the same. Pages keep their size and their order, and nothing is added to them.

What changes is how the chosen parts are stored. A form value that used to live in a field is now part of the page, in the same spot. A comment that used to be listed in the comments panel of your reader app is now part of the page too. If you open the file in a reader, you will see the same page, but the comments list and the form tools will have nothing left to show.

In the image mode, the whole page becomes a picture, so the page looks the same but every part of it is now pixels. That is why the text can no longer be selected, and why the file size depends on the DPI you choose.

Form fields are the text boxes, check boxes, radio buttons and drop-down lists in a fillable PDF. Each field keeps its value apart from the page, which is why anyone who opens the file can change it. When you flatten pdf form fields, each value is drawn onto the page in the same place and with the same look, and the field itself is removed.

Choose Form fields only if you want to fix the answers but keep comments as comments, for example when a colleague still needs to see review notes as notes. Choose Form fields and comments to fix both at once. In both cases the text of the answers stays real text, so it can be selected and searched.

Fill the form first. If you still need to type your answers, use Fill PDF Forms, download the filled file, then add it here. Once a form is flat, its fields are gone, so keep a copy of the fillable original in case you need to change an answer later.

Empty fields simply stop being fields. Whatever an empty field showed, such as a border or a shaded box, stays on the page as it looked, so a blank box still shows as a blank box.

Check boxes and radio buttons work the same way. A ticked box stays ticked and an empty one stays empty, and the choice can no longer be changed. A drop-down list keeps the option that was selected, shown as plain text on the page.

In PDF terms, comments are called annotations. They include highlights, underlines and strike-throughs, sticky notes, text boxes, stamps such as Approved or Draft, freehand drawings, shapes and arrows, and signatures that were added as a comment or stamp. To flatten pdf annotations, choose Comments and marks only, or Form fields and comments if the file also has fields.

After flattening, each mark is drawn into the page as it looked. A highlight becomes a yellow area behind the text, a stamp becomes part of the page, and a text box becomes ordinary page content. The marks can no longer be selected as comments, moved, edited or deleted from the comments list.

Sticky notes need a word of care. A note usually shows as a small icon on the page, while its text sits in a pop-up. After flattening, the icon stays where it was, but the pop-up text is not drawn onto the page. If the note text matters, copy it into the document or into a text box first.

Choose Comments and marks only when the form must stay fillable. The marks become fixed, while the form fields keep working, so someone else can still fill them in.

Review comments often hold names, dates and internal remarks. Before you send a file outside your team, look through the comments list in your reader app and delete any you do not want to share, then flatten the rest so they stay exactly as they are.

There are two very different things people call a signature in a PDF, and flattening treats them differently. The first is a signature you draw, type or place as a picture, often added with a sign tool or as a stamp. In the file it is usually an annotation that sits on top of the page and could be moved or deleted.

To flatten pdf signature marks of this first kind, choose Comments and marks only or Form fields and comments. The drawn or stamped signature becomes part of the page, so it can no longer be dragged away or deleted as a separate object. You can sign with Sign PDF first, then add the signed file here.

The second kind is a certificate-based digital signature, made with a digital ID or a signing service. Reader apps show it in a signature panel with a valid or invalid status. It protects the file with a cryptographic check, and any change to the file after signing breaks that check. Flattening is a change, so a certificate-based digital signature will no longer validate afterwards. The signature box may still show on the page, but it no longer proves anything.

So the order matters: flatten first, then apply a digital signature last. If you received a digitally signed PDF, keep the original file as the signed copy, and only flatten a separate copy if you need one for printing or reading.

Some PDFs have layers, also called optional content. They are common in files exported from CAD programs, maps, InDesign and Illustrator. Each layer can be shown or hidden in a reader app, so two people can see different things in the same file, and a printer may print a layer that is hidden on screen, or the other way round.

To flatten pdf layers, choose Everything (pages become images). Each page is drawn as a picture of what you see, so layers and hidden content are merged into one flat image, and there is nothing left to switch on or off. The other three options only fix form fields and comments; they leave layers as they are.

Use the image mode when layers cause trouble: a drawing that prints differently from how it looks, a print shop that asks for flat files, or a document with hidden content you do not want to send along. Because pages become pictures, the text can no longer be selected, searched or copied. Pick 300 DPI for small print and fine lines.

If you only need to hide one layer before sending, switch it off in a reader app that supports layers, print or save the view you want, and then use the image mode on that copy. That way the result shows exactly the layers you chose.

Printers and print shops sometimes handle form fields, comments and layers in their own way. A form value may be left out, a comment may print as an empty box, or a layer may print that you cannot see on screen. To flatten pdf for printing, start with Form fields and comments: everything you see becomes part of the page, and the text stays sharp at any size.

If a printer still prints something wrong, choose Everything (pages become images) at 300 DPI. Each page is then a single picture, so the printer has nothing left to interpret. 300 DPI is the usual print quality, 200 DPI is fine for office printers and gives smaller files, and 150 DPI is enough for drafts.

To save ink or toner after flattening, run the file through PDF to Black and White. For a print shop with a file size limit, Compress PDF can make the flattened file smaller.

Before you send a file to print, open the flattened copy and look through every page at full size. What you see on screen is what the printer will get, because there are no more fields, comments or layers that could be handled differently.

In the first three modes, nothing is turned into a picture. Your text, lines and images stay as they are, and the values and marks that are added to the page are drawn the same way they appeared before. That is how you flatten pdf without losing quality: the result is as sharp as the original at any zoom, and the text stays selectable and searchable.

Quality only becomes a choice in Everything (pages become images). There, each page is drawn as a picture at the DPI you pick under Image quality: 150, 200 (the default) or 300 DPI. A higher DPI gives sharper text and larger files. At 300 DPI, normal text looks crisp in print and on screen, but you lose the ability to select text, and the file is often bigger than before.

As a rule, use the image mode only when you need to merge layers or lock everything down. Use one of the other modes when quality and searchable text matter most.

Adobe Acrobat Pro can flatten forms and comments, but it is a paid app, and the free Acrobat Reader does not have a flatten option. This page lets you flatten pdf without adobe in any browser, on any computer or phone, with nothing to install and no account.

A common free trick is to print the PDF to a new PDF, using Microsoft Print to PDF on Windows or Save as PDF in a print dialog. It often fixes form values in place, but the result depends on the app, comments may be dropped, and you cannot choose what is flattened. Here you pick exactly which parts become fixed.

The flattening itself is done by MuPDF, an open-source PDF engine used by many PDF readers and tools, through its Python library PyMuPDF. It uses a function called bake, which takes each field and annotation and writes its look into the page content.

You do not need to know any of this to use the tool. Choose an option, press the button and download the result. The settings you pick are remembered in your browser for next time.

To flatten pdf on mac, open this page in Safari, Chrome or Firefox, drop your files on the box and choose an option. It works the same on any Mac, with no download. Preview on a Mac can export a PDF again, but it has no clear setting for flattening, and the results with forms and comments vary.

On Windows, use any browser in the same way. On an iPhone or iPad, open the page in Safari, tap Select PDF files and pick the file from the Files app or iCloud Drive. On Android, open it in Chrome and pick the file from your downloads or Google Drive. The flattened PDF is saved to your downloads or the Files app.

Because the work is done on our server, your phone or laptop does not need to be fast. Large files only take as long as the upload on your connection.

On a phone, the flattened PDF opens in your usual PDF viewer, so you can check it right away and then share it by email or a chat app like any other file.

You can add up to 10 PDFs at once, each up to 200 MB, by selecting them together, dropping them on the box or using Add more. Each file gets its own line with its page count, form fields and comments, and you can remove a file from the list before you start.

All files are flattened with the same option, one after the other, and the line shows which file is being worked on. If one file fails, for example because it is damaged, the others still finish and the problem is shown next to that file. When there is more than one result, you download them together as one ZIP, or save each PDF on its own from the list.

Flattening is not the same as a password. A password with Protect PDF stops people from opening or changing the file in apps that respect the protection, but the form fields and comments are still there for anyone who has the password. A flat file has no fields or comments left to change at all.

The two work well together. Flatten the file first, so that the content is fixed, then add a password if only certain people should open it. Keep in mind that anyone with a full PDF editor can still change the page content of any PDF; flattening makes changes much harder, not impossible.

Turning pages into pictures with PDF to JPG is another option, but then you have image files instead of a PDF. The image mode here gives you the same flat look while keeping a single PDF that opens, prints and uploads like any other.

If a PDF needs a password to open, the tool marks it and shows a password box next to the file name. Type the password and tap Unlock. The file is unlocked on our server and deleted right after; the password is only used to open the file. Then flatten it as usual. The flattened file has no password.

Files that are still locked are skipped when you press the button. If you do not know the password, the file cannot be flattened. After flattening, you can add a password again with Protect PDF, and to remove a password from other files, use Unlock PDF.

Your files are sent over an encrypted connection to our server, flattened, sent back and deleted right after. They are not kept, shared or used for anything else, and no account is needed.

The count of pages, form fields and comments happens in your browser before anything is sent. Your chosen settings are remembered in this browser, so your next visit starts with the same choices.

When you add a PDF, a PDF engine running in the page opens it and counts the form fields and the comments and marks on each page, so you know what will change. When you press the button, each file is sent to our server on its own, one after the other.

On the server, PyMuPDF opens the file and, depending on your choice, bakes form fields, annotations or both into the page content. In the image mode, each page is drawn at the DPI you chose and a new PDF is built from those pictures. The finished PDF is sent back, named with -flattened at the end unless you turned that off, and the server copy is deleted.

Keep the original. Flattening cannot be undone, so save the fillable or editable version before you flatten a copy.

Check the count before you start. If the line under a file shows the form fields and comments you expected, the default option will fix them all.

Leave the -flattened ending on, which is the default, so you can tell the final copy from the original at a glance.

Flatten before you sign digitally, and before you combine forms that might share field names.

Once your file is flat, you can join it with other documents in Merge PDF, add a password with Protect PDF, or make it smaller with Compress PDF before you email it. To share single pages as pictures, use PDF to JPG.