Text Compare & Online Diff Checker (Line, Word, Character)
Free online text compare and diff checker tool. Instantly inspect differences between two versions of text, source code (JavaScript, Python, JSON, SQL, HTML, CSS), Markdown, or legal contracts. Features side-by-side Split view and unified Inline view, Myers token diffing by Line, Word, or Character, case-insensitive matching, whitespace tolerance, added/removed token preview pills, and direct file upload (.txt, .csv, .md, .json, .js, .py).
Text Compare & Diff Checker
Quickly detect additions, deletions, and subtle character edits between two blocks of text, code, or data files.
Diff Results
| # | Original Content | # | Modified Content |
|---|---|---|---|
| 1 | function calculateTotal(price, taxRate) { | ||
| 2 | // Calculate total with tax | ||
| 3 | var subtotal = price; | ||
| 4 | var tax = subtotal * taxRate; | ||
| 5 | var finalTotal = subtotal + tax; | ||
| 6 | return finalTotal; | 1 | function calculateTotal(price, taxRate, discount = 0) { |
| 2 | // Calculate total with tax and optional discount | ||
| 3 | const discountedPrice = Math.max(0, price - discount); | ||
| 4 | const tax = discountedPrice * taxRate; | ||
| 5 | const finalTotal = discountedPrice + tax; | ||
| 6 | return Number(finalTotal.toFixed(2)); | ||
| 7 | } | 7 | } |
Step-by-Step Instructions
Input Original & Modified Text
Paste your baseline text in the left pane and revised text in the right pane, or click 'Upload File' to load .txt, .csv, .json, .md, .js, or .py files directly.
Select Diff Granularity
Choose Line mode (for code blocks and paragraphs), Word mode (for prose and article editing), or Character mode (for subtle typo and punctuation diffs).
Inspect Visual Highlights & Export
Toggle between Split View (side-by-side panes) and Inline View (chronological feed), filter whitespace or case-sensitivity, and copy difference stats.
Key Features & Capabilities
- 3 High-Precision Diff Modes: Line-by-line block diffing, Word-level prose editing, and Character-level typo comparison
- Dual Visual Layouts: Synchronized side-by-side Split View and Unified Inline View with line numbering
- Smart Sub-Line Highlighting: Inline token badges highlight exact altered characters and words within modified lines
- 100% Private Client-Side Diff: Myers LCS algorithm computes diffs locally in browser RAM with zero server uploads
Frequently Asked Questions
How does this Text Compare tool calculate differences?
The diff engine utilizes the Myers Longest Common Subsequence (LCS) dynamic programming algorithm to calculate the minimal edit script (insertions, deletions, and replacements) between original and modified text.
What is the difference between Line, Word, and Character comparison modes?
Line mode compares full lines (best for source code and CSV data), Word mode compares individual words separated by spaces (best for essays and articles), and Character mode compares grapheme-by-grapheme (best for finding subtle typo changes).
Can I compare code files and JSON data with syntax formatting?
Yes. You can paste JavaScript, Python, JSON, SQL, HTML, CSS, Markdown, or YAML code to view color-coded green additions, red deletions, and inline modified blocks.
How do I compare two Excel or CSV spreadsheet tables for differences?
Copy and paste the tabular cells or CSV lines from both files into the left and right comparison boxes. The diff checker will highlight all differing rows, added columns, and modified values instantly.
Are my confidential contracts or code snippets uploaded to a server?
No. All text parsing, tokenization, diff computation, and DOM rendering execute 100% locally in your browser memory. Zero bytes of your documents are ever transmitted across the internet.
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