How to use this text tool
- Paste the text you want to inspect or load the sample.
- Choose only the options that match your prompt format.
- Select Compare Prompts or press Ctrl/Cmd + Enter.
- Read the summary and detailed output, then copy or download it.
System Prompt Comparator
Small edits to a system prompt can change tone, scope, or safety behavior. Put two versions into this comparator to see which lines were added, removed, or preserved. The report favors readable instruction-level changes over character-by-character noise, making it useful for reviews, change logs, and regression checks.
Text Input
Browser-only processingAd space
What this tool does
Compare two system prompts line by line and summarize added, removed, and unchanged instructions in a browser-only report.
The two prompts are split at a chosen delimiter, normalized according to the selected whitespace option, and compared with a longest-common-subsequence line diff.
Moved lines may appear once as removed and once as added. That is expected in a line-oriented comparison.
Example
Load the sample, run the tool, and compare the report with the visible markers or values in the input. The output is deterministic for the selected options, so the same text produces the same report.
Use cases
- Review a prompt before it enters a shared prompt library.
- Check generated content before another program consumes it.
- Create a lightweight audit record without uploading private text.
Tips for better output
- Keep separators and labels on their own lines.
- Use the narrowest option that matches your actual format.
- Test one valid and one deliberately invalid example.
- Review every warning in the surrounding context.
- Save the original text alongside important reports.
Processing details
The two prompts are split at a chosen delimiter, normalized according to the selected whitespace option, and compared with a longest-common-subsequence line diff. Text remains in the current browser page during processing.
Moved lines may appear once as removed and once as added. That is expected in a line-oriented comparison.
Frequently asked questions
Does System Prompt Comparator send my text to a server?
No. The processing in this page runs in your browser. Uploaded files are read locally by the page.
Can I use the result in a production prompt workflow?
Yes, but review the result first and test it with the exact model, template engine, or schema used by your application.
What happens when the input is empty or malformed?
The tool shows an input error instead of producing a misleading report. Tool-specific parsing errors include a short correction hint.
Can this tool guarantee that an AI response is safe or correct?
No. It checks the visible text using the stated rules. Model behavior, source quality, and application security still require separate review.
Is Unicode text supported?
Yes. The page accepts Unicode text, although pattern matching and token estimates may vary for scripts and formats outside the examples described.
Related text tools
Quick reference
| Item | Details |
|---|---|
| Processing | Local browser JavaScript |
| Input | Plain text or supported structured text |
| Exports | TXT, JSON, and tabular CSV when available |