Test Changes Against
Production History
Validate prompt modifications against your historical data before deployment. Catch regressions and ensure quality across all edge cases.
The Risk of Blind Deployments
Silent Regressions
Prompt changes that work on new data may break on edge cases you forgot
Lost Context
Why did you add that constraint? Production history remembers
Costly Rollbacks
Discovering issues in production means unhappy users and emergency fixes
How Backtesting Works
Comprehensive validation before you ship
1. Import History
Load your production input/output pairs as a test dataset
2. Run New Prompt
Execute your modified prompt against historical inputs
3. Compare Results
See side-by-side diffs and quality metrics
4. Ship Safely
Deploy with confidence knowing all cases pass
Comprehensive Testing Features
Dataset Management
Upload CSVs, connect to logs, or manually curate test cases. Tag edge cases and failure modes for targeted testing.
Diff Visualization
See exactly what changed between old and new outputs. Highlight semantic differences, not just text changes.
Regression Detection
Automatic detection of quality drops, missing information, or format violations compared to baseline.
Version Tracking
Full history of prompt versions with performance metrics. Easy rollback if issues are discovered.
Why Backtest Prompts?
Fewer Regressions
Catch breaking changes before they reach production
Faster Iteration
Ship prompt changes with confidence, not fear
Coverage
Test against every historical scenario in your dataset
When to Use Backtesting
Pre-Deployment Validation
- Validate prompt modifications
- Catch edge case failures
- Ensure backward compatibility
Model Migration
- Validate GPT-3.5 to GPT-4 migration
- Test cross-model compatibility
- Measure performance differences
Continuous Monitoring
- Scheduled regression tests
- Monitor for model drift
- Alert on quality drops
Ship Prompt Changes With Confidence
Stop breaking production with untested prompt changes. Backtest against your historical data before every deployment.
Start Backtesting