Claude Haiku 4.5 vs OpenAI gpt-oss-120b
Compare Claude Haiku 4.5 and OpenAI gpt-oss-120b on the metrics that decide an agent workload.
| Metric | Claude Haiku 4.5 | OpenAI gpt-oss-120b |
|---|---|---|
| Provider | Anthropic | Fireworks AI |
| Input / 1M | $1.00 | $0.15 |
| Output / 1M | $5.00 | $0.60 |
| Cache read / 1M | $0.10 (−90%) | $0.01 (−90%) |
| Reuse-adj @55% | $1.63 | $0.21 |
| Context | 200K | 131K |
| Cache capture | 90% | 79% |
| Warm TTFT | 110ms (−66%) | 120ms (−64%) |
| Quality index | 80 | 79 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick Claude Haiku 4.5 when it scores higher on the composite quality index, it carries the larger 200K context window, it answers faster on warm cache hits.
Pick OpenAI gpt-oss-120b when it is cheaper once prefix reuse is priced in, it is open-weights for on-prem and regulated lanes.
Claude Haiku 4.5 leads on quality while OpenAI gpt-oss-120b leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to OpenAI gpt-oss-120b and reserve Claude Haiku 4.5 for the hard requests. Zumik's aliases route between them automatically under policy.
Claude Haiku 4.5 vs OpenAI gpt-oss-120b, answered.
Is Claude Haiku 4.5 or OpenAI gpt-oss-120b cheaper?
At 55% prefix reuse, Claude Haiku 4.5 blends to about $1.63 per 1M tokens and OpenAI gpt-oss-120b to about $0.21. OpenAI gpt-oss-120b is cheaper on that basis.
Which has the larger context window?
Claude Haiku 4.5 has the larger window: 200K vs 131K tokens.
Which captures more reuse?
Claude Haiku 4.5 shows higher measured cache capture (90% 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.