Free Text Compare Tool: line and word diff in your browser
The Novaverb text compare tool shows every added, removed and unchanged line or word between two versions of a text. The comparison runs in your browser and nothing is uploaded.
Similarity is twice the number of matched units divided by the total units in both texts, so two identical texts read 100% and two texts sharing nothing read 0%.
Turn output into a monitored workflow
A Novaverb workspace crawls your live site, keeps what it finds, tracks changes over time and turns findings into assigned work.
What is a text compare tool?
A text compare tool takes two versions of a text and shows what differs between them. The Novaverb Text Compare tool marks every line or word as unchanged, added or removed, counts each group and reports a similarity percentage, with the whole comparison running in the browser.
What does the text compare tool check?
The text compare tool checks an original text against a changed text, unit by unit. In line mode each line is a unit, which suits code and configuration. In word mode each whitespace-separated word is a unit, which suits prose. Options can ignore case, ignore outer spaces and leave blank lines out of the comparison.
Who is the text compare tool for?
The text compare tool is for anyone holding two versions and no version control. An SEO checks exactly what a plugin or a migration changed on a page before launch. A developer diffs a robots.txt or a redirect map against the version about to deploy. An editor compares a draft with the published copy.
Why use a text compare tool?
A text compare tool catches a change nobody meant to make. Reading two versions side by side can miss a deleted line or a swapped word. A unit-by-unit diff confirms whether a rewritten page kept the headings, entities and claims that were meant to stay, before the new version goes live.
How does the text compare tool work?
The text compare tool works as you type. Paste the earlier version, then the newer version, and choose line or word mode. The matcher finds the longest common sequence between the texts instead of comparing position by position, marks every other unit as removed or added and updates the counters.
Compare two versions of the same text
Paste the earlier version on the left and the newer one on the right. The comparison runs as you type: every unit is marked unchanged, added or removed, and the counters show how much actually moved rather than how much looks different.
Line mode or word mode
Line mode is the right choice for code, configuration files, robots.txt, CSV rows and anything where a line is a meaningful unit. Word mode is better for prose, where a single edited word would otherwise mark a whole paragraph as changed.
Why a moved block is not reported as a rewrite
The comparison finds the longest common sequence between the two texts instead of comparing position by position. A paragraph moved further down is reported as one removal and one addition, not as every line in between having changed.
Where this helps an SEO or content workflow
- Check exactly what an editor, a plugin or a migration changed in a page before it goes live.
- Diff a robots.txt, a sitemap or a redirect map against the version you are about to deploy.
- Confirm that a rewritten page kept the headings, entities and claims you intended to keep.
- Compare a draft against the published version when you do not have version control on the content.
What do you enter into the text compare tool?
The text compare tool takes two pasted texts, labeled original and changed. Code, configuration files, CSV rows and prose are all handled as plain text. A very large paste is capped: only the first part of each side is compared, and the tool says so and states how much was compared when the cap applies.
What does the text compare tool report contain?
The text compare tool report contains counts of unchanged, added and removed units, a similarity percentage and the marked differences. Line mode shows line numbers for both sides and can display changes only. The downloadable text-diff.txt file marks each line with a leading minus, plus or space, and uses inline markers in word mode.
How do you read a text compare result?
Read a text compare result by marker. A plus marks a unit present only in the changed text, a minus marks a unit present only in the original, and an unmarked unit is in both. A paragraph that was moved appears as a removal and an addition, not as every line in between having changed.
Where does the text compare tool run?
The text compare tool runs entirely in the browser and reads only the two pasted texts. No request is sent to compare them, so a contract, an unpublished draft or a configuration file never leaves the machine. The absence of a request is also why the tool has no server-side limit.
What does the text compare tool not tell you?
The text compare tool does not tell you why something changed, who edited the text or when. Only the pasted versions are known to the tool. The similarity percentage describes this comparison and is not a plagiarism score or an originality verdict. Text beyond the comparison cap is not examined at all.
What does a text compare result prove?
A text compare result proves that the pasted texts differ in exactly the units shown, under the options selected. A diff is evidence of a change, not an explanation of a change. Nothing in the result shows which version is live on a site, or which version is the correct one to keep.
Which rules does the text compare tool apply?
The text compare tool applies a longest common sequence match over lines or words. The downloaded file follows the familiar diff convention in line mode, with a leading minus, plus or space. Word mode follows the wdiff convention with inline markers. Similarity is twice the number of matched units divided by the total units in both texts.
How can you verify a text compare result yourself?
Verify a text compare result with a case where the answer is already known. Paste the same text on both sides and confirm that similarity reads 100% with nothing added or removed. Then change a single word on the changed side, switch to word mode and confirm that only the old word and the new word are marked.
What does a typical text compare finding look like?
A typical text compare finding comes from checking a robots.txt file before deployment. Most lines read as unchanged. A Disallow line shows as removed and a broader line as added, a change nobody had mentioned. The counters confirm that nothing else moved, so the review can concentrate on that rule alone.
Is the text compare tool free?
The text compare tool is free and needs no account. Both modes, every option, copy and download work on the page. A free Novaverb account is needed only for comparisons the tool cannot make, such as measuring a live site with a crawl and monitoring how the findings change over time.
What does a Novaverb workspace add to the text compare tool?
A Novaverb workspace adds recorded history to the manual check the text compare tool performs. Site Health Audit grades each crawl of the site against a defined criteria library and keeps the history of earlier runs, so a change between releases is seen in the evidence instead of being assumed.
When is a free text compare tool not enough?
A free text compare tool is not enough when nobody saved the earlier version. A manual comparison needs both texts in hand, covers a single document per run and has to be repeated by a person. A site whose pages change between releases needs a recurring crawl that records each state.
What should you do after running the text compare tool?
After running the text compare tool, switch the view to changes only and read each removal and addition. Decide which differences were intended and reverse those that were not. Download text-diff.txt as a record of the review, then deploy the approved version and confirm that the live file matches it.
Which free tools pair with the text compare tool?
The text compare tool pairs with the Robots.txt Generator, which creates the robots.txt file whose versions are then compared before deployment. The Redirect Rule Generator writes server rules from a redirect map and flags chains and loops. The Plagiarism Checker finds potential matching sources for selected sentences, which a similarity percentage cannot do.
What do people ask about the text compare tool?
Questions about the text compare tool cover whether the text is sent anywhere and what the similarity percentage means. Others ask why there is a limit on how much text can be compared, how line mode differs from word mode, what the plus and minus markers in the downloaded file mean and whether the tool explains a change.
Is my text sent anywhere?
No. The comparison runs entirely in your browser, so a contract, an unpublished draft or a configuration file never leaves your machine. There is no request to compare, which is also why there is no server-side limit on this tool.
What does the similarity percentage mean?
It is twice the number of matched units divided by the total number of units in both texts. Two identical texts read 100%; two texts with nothing in common read 0%. It is a description of this comparison, not a plagiarism score or an originality verdict.
Why is there a limit on how much text I can compare?
The matcher compares every unit in one text against every unit in the other, so the work grows with the product of the two lengths. The cap keeps a very large paste from freezing your own browser tab. When it applies, the tool says so and tells you how much it compared.
What is the difference between line mode and word mode?
Line mode treats each line as one unit, which suits code and configuration. Word mode treats each whitespace-separated word as one unit, which suits prose - changing one word marks one word instead of the whole paragraph.
What do the plus and minus markers in the downloaded file mean?
In line mode the file follows the familiar diff convention: a leading minus is a line only in the original, a leading plus is a line only in the changed text, and a leading space is a line present in both. Word mode uses the wdiff convention instead, marking removals and additions inline.
Can it tell me why something changed?
No. It reports what differs between the two texts you pasted. It has no knowledge of who edited them, when, or for what reason - a diff is evidence of a change, not an explanation of one.
Is my data uploaded anywhere?
No. This generator runs fully client-side in your browser. Nothing you type is sent to a server, so it is safe to use on private content.
Is it really free?
Yes, with no account. A Novaverb workspace is only needed when you want your live site crawled, the results kept and changes tracked over time.