GLM-5.1 Review 2026: #1 SWE-bench Pro, MIT License, $1/M Tokens
GLM-5.1 is the first open-weight model to claim the top spot on SWE-Bench Pro, scoring 58.4 as of April 2026 — ahead of GPT-5.4 at 57.7 and Claude Opus 4.6 at 57.3. Released on April 7, 2026 by Z.AI (formerly Zhipu AI), it combines a 754B-parameter Mixture-of-Experts architecture with an MIT license and API pricing starting at $1.40 per million input tokens. For teams running high-volume code generation pipelines, that combination is difficult to ignore. ...