Is Text Diff Checker free to use?

Yes. Text Diff Checker is free, has no usage cap and does not require an account. There is no paid tier that unlocks extra output.

Does my data get uploaded to a server?

No. The tool is a JavaScript function that runs inside your browser tab. Nothing you paste or drop in is transmitted, logged or stored by us.

Do I need to create an account?

No account, no email address and no sign-in. Open the page and start working.

Does it work on a phone or tablet?

Yes. The interface is responsive and works in mobile Chrome, Safari, Edge, Firefox and Samsung Internet. You can also install Toolspea as an app from the browser menu.

Can I use the output commercially?

Yes. You keep every right you already had over the input, and we claim nothing over the output.

Is the comparison line-based or word-based?

Line-based. Each line is matched as a whole unit, which is the right granularity for code, configuration and lists. For prose, keep one sentence per line to get finer results.

Can I compare files instead of pasting?

Open the file in any editor and paste the contents. Nothing you paste is uploaded, so confidential documents can be compared safely.

Text tools

Text Diff Checker

Compare two blocks of text and highlight every line that changed.

Original text (paste the revised version below)

Result

Options

Revised text

Ignore case differences

Everything above is processed in this browser tab. Your input is never sent to a server.

What is Text Diff Checker?

Text Diff Checker compares two versions of a text and reports which lines were added, removed or left unchanged. It is used to review edits between drafts, spot an unintended change in a configuration file, or confirm that a copy revision matches what was approved.

How to use it

1Paste the original version into the main input.
2Paste the revised version into the comparison field.
3Read the line-by-line report: + marks additions, − marks removals.
4Copy the report into a review comment or changelog.

Features

Line-level comparison with add, remove and unchanged markers
Optional case-insensitive matching for style-only revisions
Counts of added and removed lines shown at the top of the output

When people use it

Approving copy revisions

When a stakeholder returns a document without tracked changes, a diff shows exactly which sentences moved rather than rereading the whole piece.

Checking config drift

Compare a working environment file against a broken one to find the single line that differs.

Known limits

Comparison is line-based, so a reflowed paragraph shows as one removal and one addition even if only a word changed.