Head-to-head showdown: Grok 4.3 ($1.25 in / $2.50 out per 1M) vs GLM-5.1 (Z.ai) ($1.40 in / $4.40 out per 1M). Grok 4.3 is 1.5× cheaper across standard token mixes, with 1M vs 200K context windows.
grok-4-3 · xai
glm-5.1 · zai
Benchmark
| Workload Scenario | Grok 4.3 | GLM-5.1 (Z.ai) | Price Delta |
|---|---|---|---|
| 1M input tokens (raw text) | $1.25 | $1.40 | −$0.15 |
| 1M output tokens (generation) | $2.50 | $4.40 | −$1.90 |
| 1M tokens · 70% input / 30% output mix | $1.625 | $2.30 | −$0.675 |
| Standard chat turn (4K in / 800 out, 50% cached) | $0.0049 | $0.00684 | −$0.00194 |
| Monthly scale (10K requests / day) | $1,470.00 | $2,052.00 | −$582.00 |
Negative difference = Grok 4.3 is cheaper. Positive = GLM-5.1 (Z.ai) is cheaper.
Scaling Curve
Total cost of a token volume at 70/30 input/output split (uncached). Log-log scale.
Verdict
Grok 4.3 is cheaper on both input and output rates, so it costs less at every input/output mix. Price alone still isn't the whole decision: capability, latency and context limits (Grok 4.3: 1M, GLM-5.1 (Z.ai): 200K) may justify the premium for your task.
FAQ
On input, Grok 4.3 is cheaper ($1.25/M vs $1.40/M). On output, Grok 4.3 is cheaper ($2.50/M vs $4.40/M). The same model is cheaper on both sides, so it wins at every mix.
A chat-style request (4,000 input + 800 output tokens, 50% cached) costs $0.0049 on Grok 4.3 and $0.00684 on GLM-5.1 (Z.ai) — Grok 4.3 is 1.4× cheaper for that workload.
Grok 4.3 supports 1,000,000 tokens (32.8K max output); GLM-5.1 (Z.ai) supports 200,000 (131.1K max output). Grok 4.3 fits 5.0× more context, which matters for long documents and agents.