Quick Take

GLM-5.2 (released June 16, 2026) and Claude Fable 5 (released June 9, 2026) represent different segments of the current AI landscape. GLM-5.2 focuses on throughput and accessibility, whereas Claude Fable 5 leverages adaptive reasoning to achieve top-tier intelligence metrics.

Benchmark Read

Claude Fable 5 consistently outperforms GLM-5.2 across all shared metrics. Claude Fable 5 records an Intelligence index of 59.9 and a Coding index of 76.5, significantly higher than GLM-5.2’s 34.1 and 46.5, respectively. In specialized benchmarks, Claude Fable 5 scores 0.926 on GPQA and 0.7 on LCR, compared to GLM-5.2’s 0.686 and 0.373. Additionally, Claude Fable 5 shows strong performance in complex tasks like TAU2 (0.985) and HLE (0.533).

Cost and Speed

There is a stark contrast in operational efficiency. GLM-5.2 is highly economical, with a blended cost of $3.16/1M tokens, compared to Claude Fable 5’s $20.00/1M tokens.

Performance metrics further highlight these differences:

• GLM-5.2: Output speed of 118.912 tok/s and a time to first token of 1.094s.
• Claude Fable 5: Output speed of 72.104 tok/s and a time to first token of 66.916s.

GLM-5.2 is optimized for rapid responses, while Claude Fable 5 requires a significantly longer initialization period, likely due to its adaptive reasoning architecture.

Best Fit

GLM-5.2 is best suited for developers and enterprises needing high-speed, cost-effective model integration for standard tasks. Claude Fable 5 is the preferred tool for complex reasoning, advanced coding, and tasks requiring high accuracy, provided the user can accommodate the higher latency and cost.