Artificial Analysis finds 1 in 4 third-party AI endpoints underperform their advertised models

Artificial Analysis released version 1.1 of its Endpoint Accuracy Index, finding that roughly one in four of more than 100 serverless endpoints scores below the reference deployment of the same open weights. The index reruns each endpoint on BFCL v4-500, HLE-250 and AA-LCR-25 and reports a 95% confidence interval, now narrowed to plus or minus 2.6 points. In the GLM-5.3 Flash results, two endpoints with output caps near 32,000 tokens fell to 22% and 29% raw HLE-250 accuracy versus 55% for the reference, while two Muse Spark Open endpoints that encoded string tool arguments as numbers scored 50% and 51% on BFCL v4-500 versus 59%.