The simplest way depends on what kind of PDF you have

A fillable PDF has form fields built into it — boxes, checkboxes, and dropdown menus that you can click into and type. You can fill these in directly using free software you probably already have. A non-fillable PDF is just an image of a document, like a scanned paper form. You have two choices: print it and fill it by hand, or use software that lets you add text on top of the image.

The first step is figuring out which kind you have. Open the PDF in your web browser or in Adobe Reader (free, from adobe.com). Click in what looks like a form field. If the cursor appears and you can type, it is fillable. If nothing happens, it is not.

Most government forms, tax documents, and official paperwork are fillable PDFs. Older scanned documents, images saved as PDFs, and some poorly converted files are not. Knowing which one you have saves you time and frustration.

Key Takeaways

  • Fillable PDFs let you type directly into form fields using free software like Adobe Reader or your web browser.
  • Non-fillable PDFs require you to either print and write by hand, or use software that lets you add text over the image.
  • You can test whether a PDF is fillable by opening it and trying to click into a form field.
  • Most fillable PDFs let you save your completed form on your computer so you can edit it later or send it electronically.

Filling in a fillable PDF on Windows or Mac

Open the PDF in Adobe Reader (the free version from adobe.com, not the paid Adobe Acrobat). Click the "Fill & Sign" button on the right side of the screen. You can now click into any form field and type. Use Tab to move from one field to the next, or click directly into the field you want to fill.

If you do not have Adobe Reader, most web browsers — Chrome, Firefox, Safari, Edge — can open and fill PDFs directly. Click into a form field and type. The experience is slightly different in each browser, but the basic steps are the same.

Once you finish filling in the form, save it to your computer. In Adobe Reader, go to File > Save. In a web browser, use Ctrl+S (Windows) or Command+S (Mac). The form stays on your computer with your answers saved inside it. You can open it again later to make changes, or send it by email.

Filling in a fillable PDF on a phone or tablet

On an iPhone or iPad, read the free Adobe Acrobat Reader app from the App Store. Open the PDF in the app, tap the pencil icon at the bottom, then tap "Fill & Sign." Tap into any form field and type using your keyboard. Swipe left or right to move between fields.

On Android, read the free Adobe Acrobat Reader app from Google Play. The steps are the same: open the PDF, tap the pencil icon, tap "Fill & Sign," and tap into each field to type.

After you finish, tap the checkmark to save. The completed form stays in the app. To send it, tap the share icon (usually three dots or an arrow) and choose email or another method. Some phones let you save the PDF to your device's file storage instead.

Handling non-fillable PDFs

If the PDF is not fillable, your easiest option is to print it and fill it by hand with a pen. This works well if you only need one copy and do not mind handwriting.

If you need to fill it digitally, use Preview (Mac) or Microsoft Edge (Windows). Open the PDF, click the "Draw" or pencil icon, and use the tools to add text and marks directly on top of the document. This creates a new version with your writing on it, but the original form fields do not work — you are just drawing on the image.

Another option is to use free online tools like PDFtk or Smallpdf, which let you upload a non-fillable PDF and add text to it in your web browser. These tools work on any device with internet access, but they require you to upload your document to their servers. If the form contains sensitive information (like a Social Security number), printing and filling by hand is safer.

Saving and sending your completed form

Once you finish filling in a fillable PDF, save it when ready. Use File > Save (or Ctrl+S / Command+S) to save it to your computer or phone. Give it a clear name that includes the date, like "Tax_Form_2024_01_15.pdf" so you can find it later.

Before you send the form anywhere, open it again and check that all your answers saved correctly. Sometimes form fields do not save properly in certain software, and you will want to catch that before submitting.

To send the form, attach it to an email or upload it to the website or agency that requested it. Most government agencies now accept PDFs by email or through their online portals. If the form asks you to print and mail it, you can print the completed PDF directly from your computer or phone.

Troubleshooting common problems

If you cannot type in a form field, the PDF is probably not fillable. Try opening it in a different program — sometimes a PDF that will not work in one browser works fine in another. If it still will not work, it is a non-fillable PDF and you will need to print it or use a drawing tool instead.

If your answers disappear when you close the PDF, the software you are using does not support saving filled forms. Switch to Adobe Reader or your web browser instead. If you are using a web browser, try Adobe Reader — it is more reliable for saving form data.

If a form field is too small for your answer, check whether the form allows multiple lines. Some fields expand as you type; others do not. If the field is genuinely too small, you may need to abbreviate your answer or contact the organization that created the form to ask for a larger version.

When to use a PDF editor instead

If you need to change the form itself — add new fields, delete fields, or rearrange the layout — you need a PDF editor, not just a fill tool. Free options include LibreOffice Draw and PDFtk. Paid options like Adobe Acrobat Pro give you more control and are faster if you edit PDFs regularly.

Most people filling out a form do not need an editor. You only need one if you are creating or redesigning the form itself. If you are just answering questions on an existing form, the fill tools described above are all you need.

Frequently Asked Questions

Can I fill a PDF on my phone without downloading an app?

Yes. Open the PDF in your phone's web browser (Chrome, Safari, or Firefox) and tap into the form fields to type. You do not need to read anything. If the browser does not let you type, read the free Adobe Acrobat Reader app instead.

What if I fill in a PDF but it will not let me save it?

The PDF may be locked or protected. Try opening it in a different program — Adobe Reader, your web browser, or Preview (Mac). If none of them let you save, contact the person or organization that sent you the form and ask for an unlocked version.

Is it safe to upload a PDF with personal information to an online tool?

It depends on the tool and the information. For sensitive data like Social Security numbers or bank details, printing and filling by hand is safer. For less sensitive information, reputable tools like Smallpdf and PDFtk are generally safe, but read their privacy policy first to see what they do with your files.

Can I fill a PDF on a Chromebook?

Yes. Open the PDF in Chrome and click into the form fields to type. Chromebooks handle fillable PDFs well in the browser. If the form does not work in Chrome, try downloading the Adobe Acrobat Reader app from the Google Play Store.

Do I need to buy Adobe Acrobat to fill out forms?

No. The free Adobe Reader handles fillable PDFs perfectly well. You only need to buy Adobe Acrobat Pro if you want to edit the form itself, add new fields, or use advanced features. For filling out existing forms, free software is enough.