We audited LoCoMo: 6.4% of the answer key is...

Projects are still submitting new scores on LoCoMo as of March 2026. We audited it and found 6.4% of the answer key is wrong, and the LLM judge accepts up to 63% of intentionally wrong answers. LongMemEval-S is often raised as an alternative, but each question's corpus fits entirely in modern context windows, making it more of a context window test than a memory test. Here's what we found. LoCoMo LoCoMo (Maharana et al., ACL 2024) is one of the most widely cited long-term memory benchmarks. We c