Online Diff Checker | Compare text, PDF and Word files side by side for free

Place them side by side and the changed clauses stand out in color. Even a one-character change in an amount or date is pinpointed.

When the other party sends a revised version, tracking every change by eye just isn’t realistic. Put the before and after versions side by side and only the changed clauses light up in color. Single-character differences in amounts or dates are highlighted character by character, so nothing slips past.

Documents received as PDFs can be loaded as they are. Files are never sent anywhere, so it’s safe for contract data from business partners.

Compare the old and new versions to see added and deleted paragraphs at a glance.

With documents edited by several people, it’s easy to lose track of what was touched. Compare the old and new versions and you can tell added and deleted paragraphs apart at a glance. You can also review each change and copy across only the ones you want to keep.

Source code, JSON, XML and logs are supported. To ignore indentation-only differences, use “Ignore all whitespace”.

Putting the config files from a working and a broken environment side by side can reveal the one line causing the problem. Because text formats such as source code, JSON, XML and logs are supported, it’s useful for development and maintenance too — for example, comparing your local source with what’s actually deployed to catch missed changes. To ignore indentation-only differences, turn on “Ignore all whitespace”.

Put the drafts before and after proofreading side by side, and only the edited parts stand out in color.

As you revise a text, you can lose track of what you changed and how. Compare the before and after versions and only the rewritten sentences are highlighted, so you can reread them with the intent of each edit in mind.

You can also check a draft returned by an editor against your own copy, and copy across only the corrections you want to accept.

Put a translation next to its source text to spot untranslated or missing paragraphs.

When a translation comes back, matching each paragraph to the original one by one takes time. With the original and the translation side by side, you can check at once whether the paragraph counts match and whether anything was left untranslated.

It works the same way for comparing a rewritten article with the original to see how much was changed.

Line-level comparison shows structural changes; character-level shows fine detail. This tool combines both.

Text comparison works at two main levels of detail. Line-level comparison determines which lines were added, deleted or changed. It’s good for understanding structural changes across a document, but it can’t tell you where within a changed line the change is.

Character-level comparison pinpoints exactly which characters in a line changed. It’s ideal for spotting small differences, such as “April 1, 2026” becoming “April 30, 2026”.

This tool combines both. It first matches lines, then compares changed lines character by character and highlights only the parts that changed in a darker color — so you see structural and detailed changes at the same time.

Only the body text is compared. Layout differences, scanned PDFs and the old .doc format are not supported.

For PDF and Word (.docx) files, the body text is extracted and then compared. Layout differences such as fonts, text color, table borders or image positions are therefore not detected. Think of it as a way to see how the wording changed.

Only PDFs that contain real text can be compared. In a PDF made by simply scanning paper, the text is stored as an image, so it can’t be compared as is. The old Word format (.doc) isn’t supported either — re-save the file as .docx before loading it.

It runs entirely in the browser, so no admin rights are needed. To compare whole folders, dedicated software is the better fit.

It’s common for work computers to lack admin rights, so you can’t install new software. This tool runs entirely in the browser, so it works regardless of what you’re allowed to install — and it works the same on a Mac.

As a rule of thumb: if you need to compare entire folders or run comparisons every day, use installed software; if you just want to compare two documents you have right now, use this tool.

Text files (.txt / .md / .csv / .log / .json / .xml / .html) as well as PDF and Word (.docx).

For PDF and Word, the body text is extracted and then compared, so differences in layout or images are not detected.

PDFs without a text layer (simple scans of paper) and the old Word format (.doc) can’t be loaded — re-save as .docx first. You can also paste text directly instead of using files.

Green means a line only on the right (added), red a line only on the left (deleted), and yellow a line whose content differs (changed).

These three colors follow the “added / deleted / changed” convention commonly used in text comparison (diff) tools.

Yellow lines are further compared character by character, and only the characters that actually changed are shown darker — so even a one-character change in a date or amount won’t be missed.

Yes. Each press of “🔎 Show all” cycles through all → diffs only → matches only (Ctrl+D).

In “Diffs only” view, matching lines are collapsed and only the differing parts are listed — ideal for finding changes in long documents. You can also step from one difference to the next.

Yes. Click a changed line to rewrite it directly. There are also buttons to copy content from one side to the other.

The “Left to right” and “Right to left” buttons copy the selected lines to the other side, so you can decide line by line which version to keep.

Your edits are reflected right in the comparison view. When you’re done, go ahead and save.

Yes. Four options are available: “Ignore case”, “Ignore leading/trailing spaces”, “Ignore all whitespace” and “Ignore page-number lines”.

Use “Ignore all whitespace” for files that differ only in indentation, and “Ignore leading/trailing spaces” when trailing spaces crept in while copying.

Settings apply to the result immediately, so you can toggle them to narrow things down to the real differences.

Yes. You can save the edited left and right texts (.txt) and the color-coded comparison (.html).

An .html file opens in any browser with the colors intact — useful for sharing your review with others or keeping it on record.

A general term for tools that compare two texts or files and detect what changed.

“diff” originally comes from software development, where it referred to a command that compares old and new source code and outputs the added, deleted and changed lines. Today it’s used for any tool that finds differences between texts or data.

HANEHikaku does the same thing as diff, right in your browser. No installation or command line needed — just paste two texts or load two files, and the changes are shown in color.