Head-to-head
Claude Sonnet 4.6 vs GLM 5.1
Compare Claude Sonnet 4.6 and GLM 5.1 on the metrics that decide an agent workload.
| Metric | Claude Sonnet 4.6 | GLM 5.1 |
|---|---|---|
| Provider | Anthropic | Fireworks AI |
| Input / 1M | $3.00 | $1.40 |
| Output / 1M | $15.00 | $4.40 |
| Cache read / 1M | $0.30 (−90%) | $0.26 (−81%) |
| Reuse-adj @55% | $4.89 | $1.68 |
| Context | 1M | 203K |
| Cache capture | 94% | 83% |
| Warm TTFT | 190ms (−65%) | 130ms (−62%) |
| Quality index | 88 | 89 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick Claude Sonnet 4.6 when it carries the larger 1M context window, it captures more of the available reuse.
Pick GLM 5.1 when it scores higher on the composite quality index, it is cheaper once prefix reuse is priced in, it answers faster on warm cache hits.
GLM 5.1 wins on both reuse-adjusted cost and quality here, so it is the default pick. Reach for Claude Sonnet 4.6 only when a specific constraint (modality, latency floor, or licensing) forces it.
Frequently asked
Claude Sonnet 4.6 vs GLM 5.1, answered.
Is Claude Sonnet 4.6 or GLM 5.1 cheaper?
At 55% prefix reuse, Claude Sonnet 4.6 blends to about $4.89 per 1M tokens and GLM 5.1 to about $1.68. GLM 5.1 is cheaper on that basis.
Which has the larger context window?
Claude Sonnet 4.6 has the larger window: 1M vs 203K tokens.
Which captures more reuse?
Claude Sonnet 4.6 shows higher measured cache capture (94% vs 83%) 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.