PDF files are hard to edit, but these four free apps make it easy.

Sending PDF files is quite simple, but its editing can prove tedious, especially on the relatively small screen of your phone. Fortunately, I found easy and quick ways to edit a PDF file on an iPhone ($ 1,000 at Amazon) and Android phone, as well as on Mac and PC. I will explain the basics, such as adding text, signing documents and completing forms. And the best part is that all the apps and software I recommend here are free.

If you want to follow or see a preview, watch the video at the top of the story.

Editing a PDF on a Mac

Each Mac comes with a program called Preview from Apple. You can use it to view and edit photos and PDFs.

To begin, simply double-click on your PDF file and it should open automatically in Preview. If this does not happen for any reason, open your Applications folder and open Preview. It is the icon with a postcard of the ocean and a small magnifying glass on the corner. From there, a window asks you to select the desired file and when you are ready click on the blue button. Open button and you are back in the game.

To access the toolbar, click on the button Marking tool at the top right next to the search box. The icon is a pencil tip inside a circle. Click on Text tool – this is the icon of a letter T inside a square – and a text box appears in the middle of your document. You can move the box anywhere on the page.

To change the appearance of the text, press the Text style tool – this is the icon with italic A. If you need to resize the text box, click on one of the blue dots. This will allow you to expand or expand the text field by dragging them left or right.

There are also tools for drawing and drawing. the Draw tool allows you to draw just about anything you want with your cursor while the Sketch tool turns objects you draw into shapes with a customizable fill and border. If you simply draw a line or a squiggle, you can change the color and thickness using the keys Style of form tool – parallel lines stacked – or Border tool – the small square inside a large square. If you do not feel particularly artistic, you can also add predefined shapes.

Maybe my favorite tool is the ability to add a signature. Click on the arrow next to Sign tool – the cursive letter J – and click on the button Create a signature. You must be able to use your trackpad to sign your signature with your finger or scan it with the built-in camera of your Mac.

To use the trackpad, click on the button trackpad tab and then press the Click here to start button then once you have finished signing press any key. If you like your signature, press Completed. The other way to create a signature is to sign your name on a blank sheet of paper and scan it. Instead of trackpad tab, choose the Camera tongue. Place the piece of paper in front of the camera and line up your signature on the black line. After a moment, your signature will appear on the screen in the camera preview. If you like it, press Completed.

To add one of your stored signatures, simply click on the one you want in the drop-down menu. Sign menu. Then drag it, resize it and reposition it where your signature needs to go.

Finally, to save the changes, simply press save. You can also export your changes and create a new PDF file.

Mark Up mode on the iPhone

Just like the Mac, you do not need a special application for basic changes on an iPhone. Instead of Preview, there is the Mark Up mode. Whether you want to edit a PDF in an e-mail or a file saved in the Books app, press the button To mark fashion icon – circle with a pencil tip – to start. These are actually the same tools that appear on your screen after taking a screenshot.

At the bottom of the screen you will find various tools: a highlighter, a pen, a pencil and an eraser. You can also tap the plus sign to the right to add text boxes, shapes, magnifying glass, and even signatures.

If you have a signature saved in Preview on your Mac, your iCloud account will sync it automatically with Annotation mode on your iPhone. To add a new one directly to your phone, press Add or delete a signature, then touch the plus sign at the top left of your screen. Use your finger to connect to the line and press Completed to save.

When you add changes to your PDF file, you can use the right and left arrows at the top to move forward or backward sequentially in your additions. But there is also an eraser that can be used to delete unwanted drawings, sketches, or highlights, regardless of their order.

When you have completed your changes, you can reply by email with your updated PDF file or, if you are in Books, you can delete it, send it by e-mail or print it via the menu iOS sharing.

Adobe Fill & Sign on Android

Unfortunately, there is no system-level PDF editing tool built into the Android operating system, but fortunately there seems to be an endless list of applications for editing PDF files in the Google Play Store. . For the basics, especially forms, I like Adobe Fill and Sign, which is free on the Play Store.

To begin, open Adobe Fill and Sign and choose your PDF file. The first time you open the application, you have the option to configure the application so that it opens by default each time you open a PDF file. Once your file is open, tap anywhere on the screen, add a text box. Once you have entered text, you can move the box by tapping and dragging. You can resize it using large and small letters as in the top bar of the text box.

Adding signatures and initials is easy. Adobe Fill & Sign limits you to a signature and a set of initials. The first time you tap the tool, a signature line will appear on the screen. Use your finger to sign your signature or initials. If you want to modify your registered signatures or initials, simply press the button X on the right side of the tool.

Your signature or initials will appear on your document in a resizable box that can also be moved and repositioned. There is a small blue circle with white arrows on the left and right on the right side of the box. Tap and drag the circle to the left or right to enlarge or reduce it.

Adobe Fill & Sign also has a profile where you can store information such as your address and email to feed forms. When you need to add this information to a PDF form, just tap the field you want to fill in, and then tap the information you saved in the same field in your profile.

As you make changes, Adobe Fill & Sign saves as you go. When you are done, you can send your PDF file by email and then save it to Google Drive or other apps via the Android sharing menu.

Adobe Acrobat Reader DC on PC

If you use a computer, I recommend that you download Adobe Acrobat Reader DC. This is a free and reduced version of Adobe Acrobat Pro DC that costs $ 15 a month or $ 180 a year. Reader DC has many powerful tools for basic editing. If you are in an environment composed of both PC and Mac, there is also a Mac version.

Open Reader and choose the file you want to edit. There is a Tools tab that allows you to select different sets of tools depending on the changes you want to make. Adobe Fill & Sign is one of the tools available.

In the toolbar, you can add text boxes, signatures, initials, shapes, and checkboxes. It works very similar to the way Preview does.

One of my favorite tools in Acrobat Reader is the buffer tool. Click on Tools tab, and open the Stamped set of tools. The toolbar will now have a Stamped tool and a Stamped palette of tools including a number of types of stamps from which you can choose, such as "Approved", http://www.cnet.com/ "Sign here" and "Confidential", among others.

When you have completed your PDF edits, you can save or export them as a new PDF file or in a different file format, such as Word Doc.

Now that you have several ways to edit a PDF file, take a look at our video on creating your own GIF file below.

Originally released on August 12th.