A Balatro seed is the code that determines the random sequence for a run. The same version, deck, stake, and unlock state are required to reproduce the same route.
Seed Lab helps you inspect that route before committing to a run. Start with the Balatro Seed Analyzer, then compare the early Antes, Boss Blinds, Vouchers, Tags, shops, booster packs, and The Soul results.
For background on why settings matter, read How Balatro seeds work.
Seed Lab is an unofficial fan-made project. Supported versions and analysis boundaries are shown in the tool. Results should be treated as a planning aid until the corresponding engine implementation is verified.