String Diff
Compare two short strings character by character and see exactly which characters were added or removed between them.
Recommended Settings
Pro Tips
- •Green highlighted characters were added in the 'Changed' string; red, struck-through characters were removed from the 'Original'
- •This compares individual characters, so it's best for short strings like usernames, codes, or single sentences
- •For comparing whole paragraphs or documents line by line, use the Text Diff tool instead
- •Even a single added or removed character - like a typo fix - will be clearly highlighted
Most Popular
Most users paste two short strings, like a username or product code, to spot exactly what changed
When to Use This Tool
Find the exact character that differs between two similar strings.
Verify whether two short identifiers are truly identical or subtly different.
Confirm exactly what was changed in a short piece of edited text.
Visually identify why two strings that look the same aren't matching in code.
How It Works
Split both strings into individual characters
Compute the longest common subsequence of characters shared between both strings
Mark any characters outside that shared sequence as added or removed, and display everything in order
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Client-side LCS-based character diff algorithm for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
Is this comparison case-sensitive?
Yes, 'A' and 'a' are treated as different characters.
Is there a length limit?
Yes, each string is limited to 3,000 characters to keep the comparison fast. For longer text, use the Text Diff tool, which compares by line instead of by character.
What do the colors mean?
Green highlights mark characters added in the 'Changed' string, while red, struck-through characters mark characters removed from the 'Original' string.
Is my data sent to a server?
No. The comparison runs entirely in your browser.
What's the difference between this and Text Diff?
This tool compares character by character, ideal for short strings. Text Diff compares line by line, better suited for documents, code, or longer content.