About this text diff checker
Compare two blocks of text line by line and see what was added, removed or unchanged. Both texts are split into lines and compared using a longest-common-subsequence match. Matching lines are marked unchanged; lines only in the changed text are added, and lines only in the original are removed. Use this workspace to prepare a result you can review before putting it to use. All processing takes place on your device, without an account or an upload of your inputs. Check the examples to understand the expected output, read the limitations for the supported scope, and reset the form when you want to start a separate task.
How the text diff checker works
Both texts are split into lines and compared using a longest-common-subsequence match. Matching lines are marked unchanged; lines only in the changed text are added, and lines only in the original are removed.
Text Diff Checker examples
Two texts differing only on line 1 of 2
1 line added, 1 line removed, 1 line unchanged
Two identical two-line texts
0 added, 0 removed, 2 unchanged (Identical: Yes)
Limitations & privacy
Comparison is exact, line-by-line, case-sensitive and whitespace-sensitive; it does not detect partial or word-level changes inside a line. Use at most 2,000 lines and 50,000 characters in each text.
Inputs and results stay in this browser. Only tool identifiers are stored for your recently used tools. You can clear that history from the directory.
Text Diff Checker: frequently asked questions
How does the text diff checker work?
Both texts are split into lines and compared using a longest-common-subsequence match. Matching lines are marked unchanged; lines only in the changed text are added, and lines only in the original are removed.
What can I inspect in the text diff checker result?
The line-by-line comparison helps you check the result before using it. Comparison is exact, line-by-line, case-sensitive and whitespace-sensitive; it does not detect partial or word-level changes inside a line. Use at most 2,000 lines and 50,000 characters in each text.
Does the text diff checker upload my input?
Processing happens in your browser. No tool input or output is uploaded to a server. Use Reset to clear the current workspace before starting a separate task.
Updated September 26, 2026