Capability · Comparison
Claude Haiku 4.5 vs GPT-4o
Claude Haiku 4.5 (Anthropic, 2025) is the newest small model in the Claude 4.x family, tuned for cheap, fast, tool-using agents. GPT-4o (OpenAI, May 2024) is the flagship-turned-workhorse that defined multimodal chat. As of 2026, Haiku 4.5 typically wins on cost and agentic reliability; GPT-4o wins on native audio ecosystem.
Side-by-side
| Criterion | Claude Haiku 4.5 | GPT-4o |
|---|---|---|
| Release year | 2025 | 2024 |
| Context window | 200k tokens | 128k tokens |
| Multimodal | Text + vision | Text + vision + audio |
| Pricing ($/M input) | ≈$1 | ≈$5 |
| Pricing ($/M output) | ≈$5 | ≈$15 |
| Tool-call reliability | Very strong for its tier | Strong, mature ecosystem |
| SWE-bench Verified | ≈48% | ≈33% |
| Interactive latency | Fast | Fast |
Verdict
For new agent backends and cost-sensitive workloads in 2026, Claude Haiku 4.5 is the better default — it's newer, cheaper, and meaningfully stronger on tool-calling and coding than GPT-4o. GPT-4o retains an edge if you specifically need the native-audio Realtime API ecosystem (or you're standardised on Azure OpenAI). For most other small-model workloads, the correct frame is Haiku 4.5 vs GPT-5-mini — not vs legacy GPT-4o.
When to choose each
Choose Claude Haiku 4.5 if…
- You're building an agent backend that makes many tool calls.
- Cost and latency dominate the design.
- You need 200k context at small-model pricing.
- You're happy on Anthropic API / Bedrock / Vertex.
Choose GPT-4o if…
- You specifically need the Realtime API for native audio.
- You're on Azure OpenAI and pinned to GPT-4o for stability.
- You need the mature Assistants / Batch ecosystem.
- You have existing GPT-4o eval harnesses you can't migrate yet.
Frequently asked questions
Is Haiku 4.5 really stronger than GPT-4o?
On coding agents and tool use — yes, by a clear margin. On general chat quality they're closer. GPT-4o still wins on native audio because Haiku 4.5 has no audio input.
Shouldn't I be comparing Haiku 4.5 to GPT-5-mini or GPT-4.1-mini instead?
Yes — that's the fair 2026 comparison. We cover Haiku 4.5 vs GPT-4o because many teams are still on GPT-4o and asking whether to move. The answer is usually yes, either to Haiku 4.5 or to GPT-5-mini.
Which is cheaper for a chatbot at 10M tokens/day?
Haiku 4.5 by about 5x on input and 3x on output. For a 70/30 input/output split at 10M tokens/day, that's roughly $14/day vs $65/day at list prices.
Sources
- Anthropic — Models overview — accessed 2026-04-20
- OpenAI — GPT-4o — accessed 2026-04-20