Text Compare
Compare two pieces of text and highlight the differences line by line.
How to Compare Two Texts
- 1
Paste original
Paste your original text into the left input box.
- 2
Paste modified
Paste the modified text into the right input box.
- 3
View diff
Added lines appear in green, removed lines in red, unchanged in gray.
- 4
Adjust options
Use options to ignore case, trim whitespace, or skip empty lines.
- 1
Paste original
Paste your original text into the left input box.
- 2
Paste modified
Paste the modified text into the right input box.
- 3
View diff
Added lines appear in green, removed lines in red, unchanged in gray.
- 4
Adjust options
Use options to ignore case, trim whitespace, or skip empty lines.
Text Compare Features
When You Need a Text Compare Tool
Document Revision
Compare two versions of a document to see what changed between revisions.
Code Review
Compare code snippets to identify changes, additions, and deletions between versions.
Translation Comparison
Compare original and translated text to verify completeness and accuracy.
Content Verification
Verify that edits and revisions are correct by comparing before and after versions.
Understanding the Diff Output
The comparison uses the Longest Common Subsequence (LCS) algorithm, which finds the longest sequence of lines that appear in both texts in the same order. Lines not in this common sequence are marked as added (in the modified text only) or removed (in the original only). The result is a minimal set of changes that transforms the original into the modified version.
The diff is line-based, not word-based. If a single word changes within a line, the entire line is marked as removed and a new line is marked as added. This matches how most version control systems (like Git) display diffs. The summary at the top shows the total count of added, removed, and unchanged lines for a quick overview of how much changed.
Common Text Compare Problems & Fixes
| Problem | Cause | Fix |
|---|---|---|
| Entire text shows as changed even for small edits | A single character change on a line marks the whole line as changed, because the diff is line-based. | For small edits, review the highlighted lines manually. If you need word-level diff, use a dedicated diff tool that supports character-level comparison. |
| Lines that look identical are marked as different | There may be invisible whitespace differences (trailing spaces, tabs vs spaces) between the two versions. | Enable "Trim whitespace" to ignore leading and trailing spaces before comparison. This usually resolves false differences. |
| Bangla text shows as boxes in the diff output | Your browser or operating system lacks a Bengali Unicode font for rendering the diff display. | Modern Windows, macOS, Android, and iOS include Bengali fonts by default. Try updating your browser or installing Noto Sans Bengali. |
| Comparison results differ from another diff tool | Different diff algorithms (LCS, Myers, Histogram) may produce different but equally valid change sets for the same input. | This is normal. Our tool uses the LCS (Longest Common Subsequence) algorithm, which is the most common line-based diff method. Both results are correct — they just represent different minimal change paths. |
Frequently Asked Questions
How does the text comparison work?
The tool uses the LCS (Longest Common Subsequence) algorithm to find the differences between two texts. It splits both texts into lines and performs a line-by-line diff, highlighting added lines in green and removed lines in red.
Can I compare Bangla text?
Yes. The comparison works with any text, including Unicode Bangla. The diff algorithm operates on a line-by-line basis, so it works equally well with Bangla and English text.
What do the colors mean?
Green lines with a "+" prefix are added in the modified text. Red lines with a "-" prefix are removed from the original. Unchanged lines are shown in gray without any prefix.
Can I ignore case or whitespace?
Yes. Enable "Ignore case" to treat "Bangla" and "bangla" as identical. Enable "Trim whitespace" to ignore leading/trailing spaces. Enable "Ignore empty lines" to skip blank lines in the comparison.
Is this a word-level or line-level diff?
This tool performs line-level diff. It compares entire lines and marks them as added, removed, or unchanged. If a single word changes within a line, the entire line is marked as changed. Word-level diff within lines is not supported in this version.
Is my text uploaded to a server?
No. The comparison runs entirely in your browser using JavaScript. Your text never leaves your device, making this tool safe for sensitive or confidential documents.
Is this Text Compare tool free?
Yes, completely free. No registration, no daily limit, no character cap. All comparison happens in your browser — there is no server-side processing. You can use it unlimited times for personal, educational, or commercial work.
Can I compare text from different file formats?
The tool compares plain text only. If you need to compare content from Word, PDF, or HTML files, first copy and paste the text content from each file into the two input boxes. Formatting like bold, italic, and colors is not compared — only the raw text content is analyzed.