When your fillable PDF forms contain a font that is not the same size, the only way is to adjust the font size within the form field manually. Here in this post, we'll cover five methods to change the font size in a fillable PDF form.

How to Change the Font Size in a PDF Form on Windows

This section will introduce two PDF tools on Windows to adjust the font size in a fillable PDF form, namely ApowerPDF and Sejda PDF.


Honestly speaking, this comprehensive PDF is a totally new PDF program to the editor, and it comes as a surprise. Admittedly, ApowerPDF’s valuable features will make it a reliable working partner for those who need to process loads of PDF documents on Windows 10, 8 and 7. It integrates features related to form to enables users to insert or edit fillable forms within PDFs. More than this, its ability helps resize the font in a form field.


Step 1: Download and install this PDF application on your Windows devices;

Step 2: Open a PDF containing fillable PDF forms;

Step 3: Click on the Edit icon, and a Content Editing window will pop up on the right side of the screen;

Step 4: Select the text and choose the font size in the Setting.

Users can change the PDF form’s font type, color, alignment, and line spacing.

Apart from changing the font size, ApowerPDF can add multiple boxes and text fields to PDFs. If you need to process data from forms, it allows users to reset, import and export data within fillable form fields. In short, this is a good PDF tool that is worth trying.

Sejda PDF

Sejda PDF was born in Amsterdam and started developing PDF tools in 2010. This PDF program is available online, on MacOS, Windows, and Linux to reach a broader audience. As a device-agnostic PDF application, Sejda PDF can perform multiple PDF tasks, including adjusting the font size. Let’s see how to increase or reduce the font size in a PDF form.


Step 1: Download Sejda Desktop from the official website and install the software;

Step 2: Upload a PDF having fillable forms to the workstation;

Step 3: Click on the Edit button to switch to Edit Mode from View Mode;

Step 4: Put the cursor at the place to change the font size.

Tip:Similar to ApowerPDF, Sejda PDF allows users to change the color and font type. If needed, to bold or italicize the selected text is available with Sejda PDF.

Both of these two mentioned PDF products are easy to use when it comes to adjusting the font size. Of course, we have many suitable options, such as Foxit PDF and Nitro PDF, but if you’d like to try some new PDF tools to change the font size, Sejda PDF and ApowerPDF is worth the shot.

How to Change the Font Size in a PDF Form on Mac


If MacOS users are looking for a solution to change the font size in a PDF form, here it comes. Good news to Mac users as the inbuilt app Preview is a natural font size changer on Mac devices. They don’t even need to download and install any external PDF tools to help with form editing. Steps to adjust the font size in a PDF form are listed below:

Step 1: Open a PDF document in Preview;

Step 2: Select Tools to choose Annotate, then hit the Text ribbon;

Step 3: When all text boxes appear, click on the text in the PDF form, and then press the A-shape icon to change the editing settings, for example, font size, color, alignment, font type, and italic or bold.

Step 4: Save the changes before you close the PDF document.

Note:That’s all for changing the font size in a PDF form on Mac. However, adding or inserting a fillable form into a PDF is not an easy task. If you need to create a PDF form on the PDF, check out this article.

How to Change the Font Size in a PDF Online

Well, if you don’t either want to download any PDF programs or pay for the subscription fees, web-based PDF tools are what you need. As most online PDF products offer free tasks every day, users can make full use of it to increase or reduce the font size in a PDF fillable form.

Soda PDF

Maybe you have already heard of it. Exactly, Soda PDF has both a desktop version and an online version. Soda PDF Online shares some common features with its desktop version, such as OCR, merging, editing, splitting, converting, and compressing. As to how to set the text value in a fillable PDF form online, just follow the instructions below:


Step 1: Type the URL on the search bar;

Step 2: Click Open on the left menu to import the PDF into the Soda PDF’s workplace;

Step 3: Select Type Text in the tab of EDIT;

Step 4: Choose the text and you’ll see an Editing window appear, click on the Number option box.

With Soda PDF Online, users can change font color, size, type, bold, and italic. Once you have finished editing the PDF form, tick the “Download” on the top left menu to export the fillable PDF form. Although we have countless free PDF tools online, they cannot help with changing the font size within a PDF form.

Soda PDF Online is not a free tool to use. Unlike other online tools, it doesn’t enable users to perform PDF-related tasks for free.

Final Words

As we said previously, Internet-based PDF tools may let you down if you need to change the text value, for instance, font type, color, and font size. So we will strongly recommend comprehensive desktop PDF programs to those in need of modifying and editing PDF forms.

Common FAQ about 5 Approaches to Change the Font Size within a PDF Form Field

Q:How do I change font size in PDF fillable form with Adobe Acrobat?

As one of the most popular and powerful PDF software in the world, Adobe Acrobat integrates multiple features pertinent to editing PDF forms, have a closer look:

Step 1: Open a PDF form with Adobe, then navigate to Tools and choose Prepare Form;

Step 2: Right-click the field which needs modification;

Step 3: Go to Properties and choose Appearance;

Step 4: Adjust the font size or other settings if needed.



Roche has been an active PDF user for 6 years and tried different types of professional PDF tools (both online and desktop version) since at his bachelor degree. Now, Roche works as a columnist for SwifDoo PDF over the course of the last one year, and provides useful and practical solutions pertaining to various PDF topics for users from different features.