Bloom Filter Simulator — Interactive System Design Lab

Insert elements and query the bloom filter to experience false positives first-hand. Adjust the bit array size and hash function count to see the false positive rate change — and understand exactly why Cassandra, Redis, and databases use them.

See how probabilistic membership testing avoids expensive lookups.

This free interactive simulation runs directly in your browser — no account needed. Adjust the parameters and watch how the system responds in real time.

Concepts covered

• bloom filter
• probabilistic data structure
• false positive
• hash function
• membership testing

Read the guide

• Databases: SQL vs NoSQL — The heart of your architecture. Choosing the wrong database is the most expensive mistake you can make. Learn the 5 families of databases and when to use them.
• Performance Antipatterns — You can use the fastest language and the biggest server, but bad design will still kill you. Learn how to spot the 'N+1', the 'Sync Chain', and the 'God Object'.