GLM 5.1 vs Grok 4.3

Choose GLM 5.1 if you want…

• ✓A comparable all-rounder — they trade blows on the headline metrics.

Choose Grok 4.3 if you want…

• ✓Higher intelligence (Artificial Analysis index 53)
• ✓Faster output (~168.7 tokens/sec)
• ✓Lower price ($1.56 / 1M blended)
• ✓Larger context window (1M)

GLM 5.1

GLM-5.1 from Z.ai is built for one thing above all else: software engineering that runs on its own. A 754-billion parameter Mixture-of-Experts model, it tops the SWE-Bench Pro leaderboard at 58.4%, edging out both GPT-5.4 and Claude Opus 4.6 on real-world coding tasks. What sets it apart in practice is stamina — it can pursue a single engineering goal autonomously for up to eight hours, sustaining hundreds of iterations and thousands of tool calls without human intervention. Users consistently praise this long-horizon execution for agent-based workflows where other models stall. It also delivers fast responses, with a time-to-first-token of 1.33 seconds against a class median of 2.37 seconds. The honest trade-off: GLM-5.1 accepts text only, with no image input, making it a poor fit for visual debugging or UI-centric tasks. It also tends toward verbosity in practice, which can inflate token costs. For teams building autonomous coding pipelines, though, it earns its place at the top of the leaderboard.

Grok 4.3

Grok 4.3 made a deliberate trade: xAI stopped chasing frontier performance and built something more practical instead. The result is a model that earns its keep through native X/Twitter integration — pulling posts seconds old when news breaks — and a 1 million token context window that handles entire codebases or lengthy regulatory documents in a single pass. At $1.25 per million input tokens, it arrives 40-60% cheaper than its predecessor Grok-4, and users find real value in its DeepSearch mode, which combines live web data with X discussions in a way that rivals Perplexity for current-events research. Frontend developers report genuinely polished web UI output, moving past the "cheap AI demo" look. The honest trade-off: creative writers consistently find it too literal and verbose, and its 16-second time-to-first-token sits at the high end for reasoning models in this price range. If your work is anchored in real-time information or long-document analysis rather than narrative craft, Grok 4.3 offers a focused, cost-sensible tool.