Text comparison guide
How to compare two texts and see what changed
A useful comparison starts by deciding which version is the baseline. Put the earlier text on the left, the revised text on the right, then read the result as a description of how the right-hand version differs from the left.
A worked two-text comparison
Here is a small synthetic example. The wording is intentionally ordinary so the mechanics are easy to see.
The project meeting starts on Tuesday at 10 AM.
Please bring the draft report.
The project review starts on Wednesday at 11 AM.
Please bring the final report.
The project meeting review starts on Tuesday Wednesday at 10 11 AM.
Please bring the draft final report.
The surrounding sentence still matters because it tells you where the edits occurred. The inline highlights then narrow a changed line down to the words removed from the original and added in the revised version.
Why left-to-right direction matters
A diff is directional. Private Text Compare treats the left editor as Original and the right editor as Changed. If the newer version contains a line that did not exist in the original, that line is added relative to the left side. If a line existed on the left but is absent on the right, it is removed.
If you swap the two versions, the text is the same but the interpretation reverses: an addition can become a removal because you changed the baseline. For review work, keep the earlier version on the left unless you intentionally want the opposite perspective.
How to read unchanged, changed, added and removed rows
The aligned line is the same after the active comparison options are applied.
The row represents modified content. Specific removed and added words can be highlighted inside it.
The right-hand version contains a whole line that has no aligned counterpart in the original.
A line from the original no longer appears in the revised version at that aligned position.
Use the comparison options deliberately
Ignore case
When Ignore case is enabled, a case-only difference such as Hello versus hello is treated as unchanged for comparison. Leave it off when capitalization itself is meaningful.
Ignore surrounding whitespace
This option ignores leading and trailing whitespace on each line. It does not mean that every space inside a line is ignored. Internal whitespace can still be meaningful.
Export only after the comparison says what you expect
After comparing, you can use Copy diff, download a local .diff file, or download a local .txt report. These exports reflect the generated comparison; they are not a stored history service.
If you edit either side after producing a result, compare again before relying on the export so the visible result and exported representation correspond to the current text.
What stays private in this workflow
The actual Original and Changed text is processed in the browser page session. Private Text Compare does not upload that compared text to its own backend. The comparison content and result are transient for the current page session and clear on refresh; the existing theme preference is the small local preference that may persist.
This is a product-behavior boundary, not a claim about encryption, anonymity, or every part of the device or browser environment.