How to Spell Check a PDF — Free Proofreading Tools & Methods

You just finished a 30-page report, exported it as a PDF, and sent it off. Then you spot it — a glaring typo on page three. We have all been there. The problem with PDFs is that they were designed for presenting finished documents, not editing them. So how do you spell check a PDF after it has already been created?

It turns out there are several solid methods, from online tools that scan your entire document to simple workarounds that take just a minute. I have tested a bunch of them and broken down the best approaches right here.

Why Spell Checking PDFs Is Tricky

Unlike Word documents or Google Docs, PDFs do not have a built-in spell checker. The text in a PDF is essentially a finished layout — fonts, positioning, and formatting are all locked in. Most PDF readers like Adobe Acrobat Reader do not underline misspelled words in red the way your word processor does.

On top of that, some PDFs contain scanned images of text rather than actual selectable text. Those require an extra OCR step before you can even think about spell checking. If your PDF has selectable text, you are in luck — the methods below will work smoothly.

Method 1: Use an Online PDF Editor with Spell Check

The fastest way to spell check a PDF is using an online editor that supports real-time spell checking. Tools like PeacefulPDF's editor let you open your PDF, click on any text, and see suggestions for misspelled words right there.

Here is how to do it: upload your PDF to the editor, then click on any text block to enter edit mode. Misspelled words will typically be underlined. Right-click or tap on the underlined word to see correction suggestions. Apply the fix and download your corrected PDF. The whole process takes maybe two minutes for a typical document.

This method works best for PDFs where you need to fix a handful of typos quickly without converting the entire document.

Method 2: Convert to Word, Spell Check, and Convert Back

If your PDF has dozens of errors or you need a thorough grammar check too, converting to Word is your best bet. Microsoft Word has one of the most powerful spell and grammar checkers available, and it catches things most other tools miss.

The workflow is straightforward: convert your PDF to a .docx file using a free converter, run Word's built-in spell check, fix all the errors, and then export back to PDF. You can also use free online PDF tools that handle the conversion securely without installing anything.

The downside? Complex formatting might shift during the conversion. Tables, custom fonts, and multi-column layouts can get messy. For text-heavy documents like reports and essays, this method works great.

Method 3: Browser Extensions for PDF Spell Checking

If you open PDFs in your browser regularly, a spell check extension can save you time. Both Chrome and Firefox have built-in spell checkers that work when you view a PDF in the browser window.

For Chrome, just open the PDF file directly in the browser. Right-click anywhere on the page and make sure "Spell check" is enabled. Misspelled words in form fields and editable text areas will be underlined. This will not catch errors in regular PDF body text though — it only works on form fields and editable regions.

Grammarly also offers a browser extension that works on text you select in your browser. It is not a full PDF scanner, but if you copy-paste sections of your PDF into a text area, Grammarly will check grammar, spelling, and even tone.

Method 4: Google Docs Hack

Here is a trick I use all the time. Upload your PDF to Google Drive, then open it with Google Docs. Google will automatically run OCR on the document and convert it to editable text. From there, Google Docs' spell checker kicks in and highlights errors.

This works surprisingly well for text-heavy documents. The formatting will not be perfect, but for pure spell checking, it does the job. Once you fix everything, you can download it as a PDF again or copy the corrected text back into your original document.

Method 5: Desktop Software for Batch Spell Checking

If you work with PDFs professionally and need to check dozens of documents, desktop software is worth the investment. Adobe Acrobat Pro has a full spell checker that works directly on PDF text. It scans the entire document, flags errors, and lets you correct them without converting to another format.

For a free alternative, LibreOffice Draw can open PDFs and run its built-in spell checker. It is not as polished as Acrobat for PDF editing, but it handles basic spell checking without any cost.

Handling Scanned PDFs

If your PDF is a scanned document — meaning the text is actually an image — you need to run OCR first before spell checking is even possible. OCR converts the image of text into actual selectable text that spell checkers can work with.

Most online PDF editors include OCR as part of their toolset. Run the OCR process, then use any of the spell checking methods above. Some tools even combine both steps — run OCR and spell check in one pass.

Quick Tips for Better Proofreading

Spell checkers catch typos, but they miss context errors — words that are spelled correctly but used wrong. "Their" instead of "there," "affect" instead of "effect." For thorough proofreading, combine spell check with a grammar tool like Grammarly or the Hemingway Editor.

Reading your document backwards — last sentence first — is an old proofreading trick that forces your brain to look at each word individually instead of skimming. It sounds tedious, but it catches errors that automated tools miss.

Also, always proofread after spell checking. A spell checker will fix "teh" to "the," but it will not catch missing words, awkward phrasing, or factual errors. The best approach is automated spell check first, then a careful manual read-through.