Head-to-head
GLM 5.1 vs Grok 4.3
Compare GLM 5.1 and Grok 4.3 on the metrics that decide an agent workload.
| Metric | GLM 5.1 | Grok 4.3 |
|---|---|---|
| Provider | Fireworks AI | xAI |
| Input / 1M | $1.40 | $1.25 |
| Output / 1M | $4.40 | $2.50 |
| Cache read / 1M | $0.26 (−81%) | $0.20 (−84%) |
| Reuse-adj @55% | $1.68 | $1.13 |
| Context | 203K | 1M |
| Cache capture | 83% | 79% |
| Warm TTFT | 130ms (−62%) | 280ms (−56%) |
| Quality index | 89 | 85 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick GLM 5.1 when it scores higher on the composite quality index, it answers faster on warm cache hits, it captures more of the available reuse.
Pick Grok 4.3 when it is cheaper once prefix reuse is priced in, it carries the larger 1M context window.
GLM 5.1 leads on quality while Grok 4.3 leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to Grok 4.3 and reserve GLM 5.1 for the hard requests. Zumik's aliases route between them automatically under policy.
Frequently asked
GLM 5.1 vs Grok 4.3, answered.
Is GLM 5.1 or Grok 4.3 cheaper?
At 55% prefix reuse, GLM 5.1 blends to about $1.68 per 1M tokens and Grok 4.3 to about $1.13. Grok 4.3 is cheaper on that basis.
Which has the larger context window?
Grok 4.3 has the larger window: 1M vs 203K tokens.
Which captures more reuse?
GLM 5.1 shows higher measured cache capture (83% vs 79%) in the Zumik corpus.
Let an alias pick for you.
Route to whichever model wins under current policy automatically. Zumik resolves the alias to the best fit per request, so you never hard-code a loser.