Claude Haiku 4.5 vs GPT-5.5 Pro
Compare Claude Haiku 4.5 and GPT-5.5 Pro on the metrics that decide an agent workload.
| Metric | Claude Haiku 4.5 | GPT-5.5 Pro |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input / 1M | $1.00 | $30.00 |
| Output / 1M | $5.00 | $180.00 |
| Cache read / 1M | $0.10 (−90%) | $30.00 (−0%) |
| Reuse-adj @55% | $1.63 | $67.50 |
| Context | 200K | 1.1M |
| Cache capture | 90% | 90% |
| Warm TTFT | 110ms (−66%) | 900ms (−53%) |
| Quality index | 80 | 97 |
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 is cheaper once prefix reuse is priced in, it answers faster on warm cache hits.
Pick GPT-5.5 Pro when it scores higher on the composite quality index, it carries the larger 1.1M context window.
GPT-5.5 Pro leads on quality while Claude Haiku 4.5 leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to Claude Haiku 4.5 and reserve GPT-5.5 Pro for the hard requests. Zumik's aliases route between them automatically under policy.
Claude Haiku 4.5 vs GPT-5.5 Pro, answered.
Is Claude Haiku 4.5 or GPT-5.5 Pro cheaper?
At 55% prefix reuse, Claude Haiku 4.5 blends to about $1.63 per 1M tokens and GPT-5.5 Pro to about $67.50. Claude Haiku 4.5 is cheaper on that basis.
Which has the larger context window?
GPT-5.5 Pro has the larger window: 1.1M vs 200K tokens.
Which captures more reuse?
Claude Haiku 4.5 shows higher measured cache capture (90% vs 90%) 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.