Compare two PDF files for differences in seconds
The landlord sends back the rent agreement "with one small correction". A supplier mails a revised quotation. A tender corrigendum replaces a 40-page document, and nobody says what was altered. Reading both copies line by line takes an hour, and the eye still slides past a changed digit.
When you compare two PDF files here, the software reads both and points at the exact words that differ. A rent of 18,000 that became 18,500, a notice period that went from 60 days to 30, a clause that quietly disappeared: each one is marked, so you read only what changed.
When comparing two PDF files saves you
- Contracts, offer letters and agreements that went back and forth before signing.
- Insurance policies and bank terms at renewal time.
- Thesis chapters, reports and manuscripts returned by a guide or an editor.
- Price lists, syllabuses, government notices and tender documents that were reissued.
- Checking that a "final" PDF from the printer matches the copy you approved.
Compare PDF online without uploading anything
Documents worth comparing are usually documents worth protecting. This tool lets you compare PDF online, yet both files are opened and read by your own browser. They are never sent to our server, and we could not look at them even if we wanted to.
You can compare PDF files free, with no sign-up, no daily limit and no page limit beyond what your device's memory can hold. A pair of 100-page files takes a few seconds on a recent phone or laptop.
Can I compare PDF files offline?
You need a connection to open this page. After that the work happens on your device, and no file leaves it. If you must compare two PDF files offline from start to finish, on a machine with no internet, you need desktop software that can compare PDF documents, and most of it is paid. For everything else, this page gives you the same privacy: the documents stay with you.
You do not need an app to compare PDFs
The page runs in Chrome, Edge, Safari and Firefox on Windows, Mac, Linux, Chromebook, Android and iPhone. On a phone the two pages stack one above the other. On a wider screen you see them next to each other. There is nothing to download or update.
How the comparison works, and its limits
This is a free PDF comparison tool for text, or in plainer words a PDF difference checker. It takes the words from page 1 of the original and page 1 of the new version and finds the smallest set of insertions and deletions that turns one into the other. Then it does the same for page 2, page 3 and so on. Programmers call this a diff, which is why some people look for a PDF diff tool or type "PDF diff online" when they want to compare the difference between two PDF files.
Compare PDF side by side
Both pages are drawn in full, Original on the left and New version on the right, so you can compare the PDF side by side exactly as it will print. Use the arrows to move through the pages, or the Changed pages buttons to skip the ones that are identical. The tool opens on the first page that has a change.
Differences highlighted in green and red
Under the pages, the Text changes box shows the wording of the current page. Unchanged text is grey. Inserted words have a green background. Deleted words are red. A replaced word appears as a red and green pair, for example the old date followed by the new one. The summary line on top counts the words added and removed across the whole document.
What it cannot see
When you compare the content of two PDF files online here, content means text, not pixels. A replaced photo, a moved logo, a different font or a new colour is not counted as a change. You may still spot such things by eye in the two page views.
Pages are matched by position. If a whole page was inserted near the start, every later page is compared with the wrong partner and looks heavily changed. Fix that by removing the extra page with Organize PDF, or split out the matching page range from each file, and compare again.
Compare a PDF with a Word document, Excel sheet or JPG
Only PDFs can be selected here. So can you compare a PDF and a Word document at all? Yes, with one extra step first. The same goes for spreadsheets and pictures.
Compare PDF and Word document versions
A common case: you sent a Word file and got a PDF back, and you want to know if anything was altered. To compare a PDF to Word, first convert the Word document to PDF. Then select the two PDFs here. When you compare a PDF with a Word document this way, the wording is checked reliably. Lines may break at different places in the two files, and that is fine, because the comparison goes word by word. Page breaks matter more: if the text flows onto different pages, the pages stop lining up, so convert with the same page size and margins.
Compare PDF to Excel
The same route works for spreadsheets. Convert the Excel file to PDF and compare it with the PDF you were sent. A changed amount in a quotation or a statement shows up as a red and green pair. For large sheets, keep the same print layout in both versions so that the pages line up.
Compare PDF to JPG or a scanned copy
A JPG or a scanned PDF has no text to compare. If you try, the tool tells you that no selectable text was found. To compare a PDF to a JPG, turn the JPG into a PDF, then run OCR to make it searchable, and compare the result. OCR makes small reading mistakes, so expect a few false differences such as 0 and O. They are easy to tell apart from real edits.
Compare PDF with AI, or with a difference checker?
A newer idea is to compare two PDF files with AI: paste both into a chat assistant and ask what changed. It can work for a two-page letter. For anything longer it gets risky. A language model summarises, so it may skip a changed digit in a table, invent a difference that is not there, or run out of room before the last page. And your contract has been sent to a company you did not choose.
When you compare PDF documents for differences here, no AI is guessing. The checker counts every word, and a change of one character in an account number is reported the same way as a rewritten clause. Compare the PDF using AI afterwards if you want a plain-language explanation of what a changed clause means; use this page to find out exactly which words changed.
Compare two PDF files for similarities, not just differences
The same report answers the opposite question. Two essays, two tenders from different bidders, two versions of a syllabus: if you want to know how much they share, look at the grey text. Everything shown in grey appears in both files, word for word and in the same order. If almost every page is grey with only a few red and green words, the two documents are near copies. If nearly everything is coloured, they only share a topic. The totals on top give you the numbers to quote.
Compare PDF converters and export settings
You can also use it to compare PDF converters. Convert the same Word file with two different tools or two different settings, then compare the two PDFs. Every place where a converter dropped a footnote, mangled a bullet or lost a table row shows up in red. It is a quick way to check that a Word to PDF conversion kept every sentence before you send the file to a printer or an exam portal.
Do you need paid compare PDF software?
Every compare PDF software review ends with a price, and it is usually a yearly subscription. Desktop programs earn it when you need pixel comparison of drawings, or comparison built into a document management system. For the everyday case, a contract or a report that came back edited, a free browser tool that shows the two files side by side and marks the changed words does the whole job. Try this page first; pay only if you hit a limit.
Compare two PDF files on Mac, Windows, in Edge or on a phone
You do not need to install compare PDF apps. Any current browser is enough, and the steps are the same on every device.
How to compare two PDF files side by side on a Mac
The built-in PDF viewer on a Mac can open two windows, but it will not mark the differences for you. To compare two PDF files on a Mac, open this page in Safari or Chrome, drop both files in, and the pages appear side by side with the changes listed underneath. Files from a Windows PC and a Mac compare fine together; the text inside a PDF is the same on both.
Compare PDF in Edge or Chrome on Windows
The PDF reader inside Edge shows one file at a time and has no compare command, and Chrome's viewer is the same. Open this page in a new tab of Edge or Chrome instead. It runs there without an extension, on Windows 10 and 11, and on Chromebooks. Two 50-page files usually finish in a few seconds on an ordinary office laptop.
Best way to compare two PDF files, step by step
The best way to compare two PDF documents depends on what you are hunting for. For wording, numbers, dates and names, a text comparison like this one is the fastest and the hardest to fool. For layout and images, flip between the two page views. For legal papers, do both. A few habits make the result cleaner:
- Select the older file first. Green then means "new in the latest version" and red means "taken out".
- Compare like with like. Two exports from the same program give the cleanest result.
- If nearly every page is marked, suspect an inserted or deleted page before you suspect a full rewrite.
- Download the report and keep it with the signed copy. It is a simple record of what changed between drafts.
- Need to act on a change? Add notes or highlights with Edit PDF.
Compare PDF size instead of content
This tool compares words, not kilobytes. To compare PDF size, look at the two files in your file manager. Two versions with identical text can differ a lot in size, because one was exported with high-resolution images. If the larger one is too big to email, compress the PDF. The text will still match.