Text Compare & Diff
Compare two texts, documents, code snippets, or data files and see exactly what was added, removed, or changed. Your content is compared in your browser and is not uploaded to a server.
- 100% browser-based with zero external text uploads
- Line, word, character, and Smart Diff with high precision
- JSON Semantic Diff (ignores key order and formatting)
- Side-by-side, Unified, and Changes-only views
- Export as Unified Diff (.diff), standalone HTML, or Markdown
About Text Compare & Diff
Solasu Text Compare & Diff is a free, privacy-first web utility designed to inspect differences between texts, source code, documentation, and data files directly in your browser.
Unlike primitive diff tools that simply color lines red and green, Solasu incorporates Unicode Grapheme Cluster handling for complex emojis and international characters, CJK tokenization for natural Japanese and Chinese word diffs, a dedicated JSON Semantic Diff engine that normalizes key order and indentation, and virtualized rendering capable of handling large multi-thousand-line documents smoothly.
All comparisons and file generations execute locally on your device. Zero text or file data is ever transmitted to a server.
Line, Word, Character, and Smart Diff Granularity
Choose between Line, Word, Character, and Smart Diff modes depending on the nature of your comparison.
Smart Diff automatically inspects changes within lines. For small edits such as typos, variable renames, or number updates, it pinpoints the exact modified words or characters rather than treating the entire line as a complete replacement.
For non-whitespace-delimited languages such as Japanese and Chinese, Unicode-standard tokenization ensures that words are segmented naturally, avoiding single giant diff blocks.
Structural JSON Semantic Diff
When comparing JSON data, conventional text diff tools generate noise whenever object keys appear in different orders or indentation differs.
Solasu's JSON Semantic Diff parses both inputs into structured objects and normalizes key order and formatting. It cleanly reports property additions, deletions, value modifications, and type mutations (e.g., number 30 changed to string '30') with full JSON path notations (e.g., users[3].profile.email).
Side-by-side, Unified, and Changes-Only Views
Switch effortlessly between a synchronized Side-by-side view with aligned rows, a Git-style Unified view with standard hunk headers (@@ -L,N +L,N @@), and a compact Changes-Only view that collapses long stretches of identical text.
Customize context lines (1, 3, 5, or all) and expand any collapsed block with a single click.
Complete Client-Side Privacy
Whether you are comparing sensitive contracts, personal data, API tokens, or proprietary source code, Solasu safeguards your privacy.
Diff computation and parsing execute inside a Web Worker on your local machine with zero external network requests. Data is never persisted to localStorage, cookies, or any cloud database.
Frequently Asked Questions about Text Compare & Diff
Can I compare two texts?
Yes. Paste or type into the left and right panels to immediately see additions, deletions, and modifications highlighted with precision.
Can I compare text files directly?
Yes. Click 'Open File' or drag and drop files into either panel. The tool supports .txt, .md, .csv, .json, .js, .ts, .py, and any UTF-8 text file.
Can I compare by line, word, or character?
Yes. You can toggle between Line, Word, Character, and Smart Diff (which automatically picks the most readable granularity per change) from the Granularity menu.
Can I compare JSON data?
Yes. In addition to standard text diff, Solasu provides a dedicated 'JSON Semantic Diff' mode for deep structural comparison.
Can I ignore JSON key order?
Yes. In JSON Semantic Diff mode, object key ordering is normalized so that identical properties in different orders are not flagged as differences.
Can I see JSON value and type changes?
Yes. Value changes (e.g., 30 → 31) and type changes (e.g., number 30 → string '30') are explicitly detected and highlighted with their full JSON paths.
Can I compare programming source code?
Yes. The tool easily handles JavaScript, TypeScript, Python, HTML, CSS, SQL, Rust, Go, and any other programming language with non-wrapping and monospace options.
Can I ignore case and whitespace?
Yes. Options include ignoring letter case, ignoring leading/trailing whitespace, ignoring all whitespace, and normalizing multiple spaces into one.
Can I ignore line ending differences?
Yes. Normalization between Windows CRLF (\r\n) and Unix/macOS LF (\n) line endings is enabled by default.
Can I collapse unchanged sections?
Yes. Switch to 'Changes Only' view to collapse long identical blocks, displaying only your changes with 1, 3, or 5 context lines.
Can I view the diff in Unified Diff format?
Yes. The 'Unified' view mode displays standard Git-style diff output with hunk headers and unified line numbers.
Can I save the diff as a .diff file?
Yes. From the Export menu, select 'Download .diff File' to save a standard comparison.diff patch file.
Can I export the diff as an HTML report?
Yes. You can download a self-contained, standalone HTML report with embedded CSS that can be opened in any browser offline.
Can I compare Japanese, Chinese, Arabic, and other non-Latin languages?
Yes. The engine uses Intl.Segmenter and Unicode specifications for natural word tokenization in CJK languages, RTL chrome compatibility, and NFC normalization.
Can I compare emojis correctly?
Yes. Unicode Grapheme Cluster segmentation ensures complex emojis (like 👨👩👧👦 or flag sequences) and Zero Width Joiners are treated as indivisible units without fragmentation.
Can I compare large files?
Yes. Diff calculations run in a background Web Worker without freezing the UI, and virtualized viewport rendering ensures smooth scrolling for files with tens of thousands of lines.
Is my compared text sent to a server?
No. All processing and diff calculations happen 100% locally inside your web browser. Zero network requests are made.
Is my input saved?
No. For complete privacy, Solasu does not save your text to localStorage, cookies, or any database. Your content disappears when you close or reload the tab.
What is JSON Semantic Diff?
It is a structural diff engine that analyzes JSON as parsed data objects rather than plain text, ignoring key ordering and whitespace while identifying additions, removals, and value/type mutations.
How does this differ from Git diff?
While supporting Git-compatible Unified diffs, Solasu also provides synchronized Side-by-side viewing, intra-line word/character highlights, JSON semantic analysis, and standalone HTML export directly in your browser without command-line tools.