Text Comparison (Diff Checker)
Data is securely processed exclusively within your browser.
What is a Diff Checker?
ToolVill's Diff Checker is a utility that visually highlights the differences between two pieces of text. Whether you're reviewing code changes, comparing document revisions, or verifying whether two files are identical, this tool makes it easy to spot exactly what changed and where. All comparisons run entirely in your browser — no data is ever sent to our servers.
Key Features
- Unified view / Side-by-side view: Choose the layout that works best for you. Unified view shows all changes in a single scrollable list, while side-by-side view places the original and modified text in two panels for direct comparison.
- Visual highlighting: Added content is highlighted in green, removed content in red — changes are immediately visible at a glance.
- File upload support: Upload .txt files directly instead of copying and pasting large blocks of text.
- Fully private: Everything runs client-side. Your text never leaves your browser.
When should I use a Diff Checker?
- To review local changes before committing or submitting a pull request
- To track revisions between different drafts of a document or report
- To compare contract versions to detect unauthorized changes
- To compare source and translated text side by side to ensure consistency
FAQ
What's the difference between Unified view and Side-by-side view?
Unified view combines both the original and modified text into a single list, showing deleted lines in red and added lines in green in sequential order. It's great for following the overall flow of changes. Side-by-side view places the original and modified text in two separate panels so you can directly compare corresponding lines — ideal when you want to see exactly how a specific section changed.
How long can the text be?
In most environments, the tool handles tens of thousands of lines without issue. Very large texts may cause slower comparison times depending on your device. For very long documents, we recommend comparing relevant sections rather than the entire file at once.
Is my text stored or sent anywhere?
No. All processing happens locally in your browser. Nothing you type or paste is transmitted to any server. When you close the tab, the data is gone. You can safely use this tool with confidential documents, source code, or any sensitive text.
Does it work on mobile?
Yes. The tool works on mobile browsers. However, the side-by-side view is best experienced on a wider screen like a desktop or tablet. On mobile, we recommend switching to Unified view for a more comfortable reading experience.
Can I save or share the comparison results?
Currently, the tool focuses on providing real-time comparison within your browser to ensure maximum privacy. Export and sharing features are planned for a future update in a way that continues to keep your data completely local and secure.