Text Compare

Paste your first text into the left pane and your second into the right pane, then press Compare. Differences are highlighted immediately — removed content in red on the left, added content in green on the right. You can switch between side-by-side and unified views, and change the comparison granularity between character, word and line.

No. The entire comparison runs in your browser using JavaScript. Your text is never transmitted, logged or stored anywhere. You can verify this yourself: open your browser developer tools, switch to the Network tab, and run a comparison — no request carrying your text will appear. The only network activity is the page itself and, if enabled, analytics and advertising scripts, none of which receive what you typed.

This one. There is no usage cap, no signup, no watermark and no paid tier. Most online diff tools limit how many comparisons you can run per month or require an account to save results. Because this tool does all its work in your browser, it costs nothing to run and there is no reason to meter it.

To compare 2 text files, click the upload button above either pane and choose a file, or drag a file directly onto a pane. Load the original on the left and the changed version on the right, then press Compare. Supported formats include .txt, .md, .csv, .json, .xml, .html, .log and common source code files. The file is read locally by your browser using the FileReader API — it is never sent anywhere, so you can compare two text files without installing software or uploading anything.

Notepad++ has no built-in compare feature — you need the Compare plugin. Open Plugins, then Plugin Admin, tick "Compare" and click Install; Notepad++ restarts. Then open both files as tabs and choose Plugins, Compare, Compare (or press Alt+D). Differences appear side by side with added and removed lines highlighted. If you would rather not install a plugin, or you are on a machine where you cannot, you can paste or drag the same two files into the panes above and get the same side-by-side result in your browser.

A diff tool compares two versions of text and shows exactly what changed between them. The name comes from the Unix "diff" command. Developers use them to review code changes, writers use them to compare drafts, and lawyers use them to check contract revisions. The output marks each line or character as unchanged, added or removed.

Compare and contrast text structure is a term from reading and writing instruction, not from software. It describes how a piece of writing is organised when its purpose is to examine the similarities and differences between two subjects. Two patterns are common: block structure, which covers everything about the first subject and then everything about the second, and point-by-point structure, which alternates between them one feature at a time. Signal words such as however, similarly, whereas, unlike and on the other hand usually mark it. Note that this is a different idea from the text comparison this tool performs — the tool finds the literal differences between two versions of a document, rather than analysing how an essay is organised.

Line comparison treats each line as a single unit — useful for code and structured data where a whole line changes at once. Word comparison highlights individual words that changed within a line, which suits prose. Character comparison is the most granular and pinpoints single-character edits, useful for spotting typos or subtle changes in identifiers.

.docx files are not directly supported yet. To compare Word documents, open each one, select all the text, and paste it into the panes above. The comparison will work normally on the text content, though formatting differences will not be detected. Direct .docx support is planned.

Paste or upload both JSON files and use line granularity for a structural view of what changed. For consistent results, format both files with the same indentation first — otherwise formatting differences will be reported alongside real value changes. Enabling "ignore whitespace" also helps when only indentation differs.

For a cell-by-cell check, put =EXACT(A2,B2) in a third column — it returns TRUE only when the two cells match exactly, including capitalisation. Using =A2=B2 instead ignores case. To highlight the differences visually, select both columns and use Home, Conditional Formatting, New Rule, then a formula rule such as =$A2<>$B2. Those work well for short values, but they compare cell against cell and cannot show you what changed inside a longer paragraph. For that, copy the two blocks of text into the panes above and use word or character granularity — you will see the specific words that differ rather than just a TRUE or FALSE.

Upload both CSV files and use line comparison, which aligns naturally with CSV rows. Each changed row is highlighted, and switching to word or character granularity shows precisely which fields within a row differ. Large exports work fine — the comparison is limited only by your browser, not by a server quota.

Red with a minus sign marks content present in the left text but missing from the right — a deletion. Green with a plus sign marks content present in the right text but not the left — an addition. Rows where both appear are modifications. Every change also carries a plus or minus marker, so the diff is readable without relying on colour.

There is no artificial limit. Uploaded files are capped at 5 MB to keep the browser responsive, but pasted text has no cap. Very large inputs — tens of thousands of lines — will take a moment to process because the work happens on your own device rather than on a server.

No. There is no account, no email capture and no login. Open the page, compare your text, close the tab. Nothing is stored, so there is nothing to sign in to.

Yes. On narrow screens the two input panes stack vertically and the comparison switches to unified view, which is far more readable than side-by-side columns on a phone. Every feature available on desktop works on mobile, including file upload.

Tick the "Ignore whitespace" option before comparing. This collapses runs of spaces and tabs and trims each line, so differences in indentation or trailing spaces are not reported. There are matching options to ignore letter case and to ignore blank lines.

Yes. Use the Download button to save the result as a plain text file in unified diff format, with minus and plus prefixes marking removed and added lines. You can also copy the result to your clipboard.

Copy the text of both versions into the panes, or upload them if they are plain text. Word granularity is usually most useful for legal prose because it highlights the specific wording that changed rather than flagging entire paragraphs. Because the comparison happens entirely in your browser, confidential documents never leave your machine.

Yes, and it is free because of how it is built. The comparison runs on your device, so there are no server costs that would need recovering through subscriptions. The site is supported by advertising rather than by charging users or metering usage.