How to edit a PDF for free

The short answer

Drop the PDF into the editor below. Use the buttons above the page to add Text, an Image, a Rectangle, a Highlight, a Line or a White box. Each new item appears in the middle of the page you are viewing: drag it into place, resize it from the corner handle and set its color, size or font in the panel that opens above the page. Switch pages with the thumbnails on the left or the arrows.

If the PDF is a fillable form, its fields turn into boxes you can type into directly. When everything is in place, press Download edited PDF. You get a new file with edited added to its name; the original stays unchanged, so you can always start over.

What a PDF editor can and cannot change

A Word document stores paragraphs that reflow when you type. A PDF stores the final layout: every letter, line and image already has a fixed position on the page. That is why PDFs look the same everywhere, and also why changing the text inside them is hard. Even Acrobat's full editor often breaks the spacing or swaps the font when you retype a sentence.

So most PDF editing, including this tool, works by adding things on top of the page, the way you would with a pen and correction tape:

• Text: your name, a date, an answer on a printed form, a note in the margin.
• Images: a logo, a stamp, a photo of your signature (PNG with a transparent background looks best).
• Rectangles and lines: frame a paragraph, underline a figure, strike out a line.
• Highlights: a see through marker color over existing text, which stays readable.
• White boxes: cover something you do not want to show, usually before typing a correction on top.

How to correct a word or a number

Find the wrong word, press White box and drag the box over it, then resize it so it covers the word completely. If the page background is not pure white, pick the light gray swatch or Other color to match it. Then press Text, type the correct word, choose a font and size close to the original and drag it onto the white box. The Sans font matches Helvetica and Arial, Serif matches Times, and Mono matches Courier, which together cover most office documents.

Zoom in with your browser if you need to line things up precisely, and use the arrow keys to move the selected item one point at a time (hold Shift to move ten points).

Important: a white box hides, it does not delete

The white box is drawn on top of the page. The original text is still in the file underneath it. Anyone who selects the area, copies the page text or searches the document can find it. This is fine for a typo or an outdated date, but it is not a safe way to hide confidential information such as account numbers, salaries, addresses or ID numbers.

To really remove sensitive content you need redaction, which deletes the text and image data under the area. Adobe Acrobat Pro has a Redact tool for this. Another safe way is to convert the pages into images after covering them, so no text layer remains; the PDF to image and image to PDF tools on this site can do that, at the cost of the text no longer being selectable.

Filling in PDF forms

Many applications, tax forms and contracts are fillable PDFs: they contain form fields made in Acrobat, Word or another form designer. When you open one in the editor, a note tells you how many fields were found and every field becomes a box on the page. Type into text fields, tick checkboxes, pick one of the option buttons and choose from dropdown lists. Tab moves to the next field. Read only fields stay locked, and your answers are kept when you switch pages.

When you download, the answers are written into the form fields themselves. The recipient can open the file in any PDF reader and still see and change the values. If you turn on Flatten form fields, the answers are drawn into the page and the fields are removed, so nobody can change them and the document looks the same in every reader. Flatten the version you send; keep an unflattened copy if you may need to change an answer later.

A scanned form or a PDF made by printing has no fields. The editor tells you so; in that case use Text to type your answers on the lines, exactly like writing on paper.

Text in other languages and alphabets

Every PDF reader has a small set of built in fonts, and they only contain Western European letters. Text that fits in them is written with those fonts. For other letters, for example ğ, ş, ł, ő, č, Greek, Cyrillic or Vietnamese, the editor embeds the Noto Sans font in the PDF, so the text stays real text: it can be selected, copied and found by search. Serif and Mono text with such letters is drawn as a sharp image in the chosen font, with an invisible copy of the text on top, so it can still be selected and searched. Letters that Noto Sans does not include, such as Arabic, Hindi, Chinese or Japanese, are saved as a sharp image of the text, drawn at four times the screen resolution so it prints cleanly. That part cannot be selected, and the text panel shows a short note when this applies.

The same rule applies to form answers: the value itself is always stored in the field, so it can be read as data, and its look on the page is written with Noto Sans when the standard font cannot print it. Only answers in scripts that Noto Sans lacks are drawn as an image.

Tips and common problems

• Something went wrong: press Undo (or Ctrl+Z) as often as you need; Redo brings a change back.
• An item will not stay selected on a phone: tap it once, then drag. Use the corner handle to resize and the round handles to move the ends of a line.
• An image looks stretched: images keep their proportions while you resize them. Hold Shift while dragging the corner if you want to change the proportions on purpose.
• The PDF will not open or will not save: it is probably password protected. Remove the password with Unlock PDF first.
• You need to sign the document: add a photo of your signature with Image, or use the Sign PDF tool, which can also draw or type a signature.
• You need to delete or reorder pages: do that in Organize PDF before or after editing.