Claude Haiku 4.5 vs GPT-6.1 Terra
Anthropic · US | OpenAI · US · Updated June 2026
Quick verdict
Pick Claude Haiku 4.5 for fastest claude model or near-frontier coding for its tier — 73.3% on swe-bench verified. Pick GPT-6.1 Terra for $1/$5 per million tokens (cached input $0.05) - half the price of gpt-6.1 sol and gpt-5.6 terra or terminal-bench 4.0 of 50.3% at maximum reasoning effort, versus 21.5% for gpt-5.6 terra (openai-reported).
Claude Haiku 4.5 (Anthropic) and GPT-6.1 Terra (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Haiku 4.5 is anthropic's fastest, most compact model — built for speed and volume. GPT-6.1 Terra is openAI's October 26, 2026 mid-tier model - a 1.05M-context, computer-use-capable GPT at $1/$5 per million tokens, half the price of its predecessor. Their biggest split is context window, and the breakdown below shows exactly how that plays out for your workload.
Key differences at a glance
- ▸Context window: GPT-6.1 Terra holds 5.3× more — 1.05M tokens (~1,575 pages) vs 200K (~300 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
- ▸Recency: GPT-6.1 Terra is the newer model by about 13 months (released October 26, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Claude Haiku 4.5 | GPT-6.1 Terra |
|---|---|---|
| Provider | Anthropic (US) | OpenAI (US) |
| Released | October 15, 2025 | October 26, 2026 |
| Context window | 200K (~300 pages) | 1.05M tokens (~1,575 pages) |
| Price (in/out) | $1/$5 per 1M tokens | $1/$5 per 1M tokens |
| Open weight? | No — API only | No — API only |
| Modalities | text, image, code | text, image, code |
| SWE-Bench Verified | 73.3% | Not published |
| MRCR v2 @ 1M | Not published | Not published |
Who wins what
Fastest Claude model
Claude Haiku 4.5
Claude Haiku 4.5 lists fastest Claude model among its strengths; GPT-6.1 Terra does not.
Near-frontier coding for its tier — 73.3% on SWE-Bench Verified
Claude Haiku 4.5
GPT-6.1 Terra is comparatively weak here — openAI still positions Sol and Astra as the higher-capability choices for demanding coding problems
Low-latency, high-volume API calls
Claude Haiku 4.5
Claude Haiku 4.5 lists low-latency, high-volume API calls among its strengths; GPT-6.1 Terra does not.
$1/$5 per million tokens (cached input $0.05) - half the price of GPT-6.1 Sol and GPT-5.6 Terra
GPT-6.1 Terra
Its 1.05M tokens window holds about 5.3× more than Claude Haiku 4.5's 200K in a single prompt.
Terminal-Bench 4.0 of 50.3% at maximum reasoning effort, versus 21.5% for GPT-5.6 Terra (OpenAI-reported)
GPT-6.1 Terra
Claude Haiku 4.5 is comparatively weak here — not for deep reasoning
1.05M-token context with up to 128K output tokens, plus image input and computer use via the Responses API
GPT-6.1 Terra
Claude Haiku 4.5 is comparatively weak here — smallest context in the family (200K)
Largest single-prompt input
GPT-6.1 Terra
Its 1.05M tokens window is about 5.3× larger than Claude Haiku 4.5's 200K, fitting roughly 1,575 pages in one prompt.
Which should you pick?
Someone analysing very long documents or codebases
→ GPT-6.1 Terra
Larger 1.05M tokens window fits more in one prompt.
Anyone whose priority is fastest claude model
→ Claude Haiku 4.5
It is specifically built for that.
Anyone whose priority is $1/$5 per million tokens (cached input $0.05) - half the price of gpt-6.1 sol and gpt-5.6 terra
→ GPT-6.1 Terra
That is its strongest area.
Claude Haiku 4.5: where it fits
Anthropic's fastest, most compact model — built for speed and volume. Released October 15, 2025 by Anthropic, it is built for fastest Claude model, near-frontier coding for its tier — 73.3% on SWE-Bench Verified, low-latency, high-volume API calls, and cheapest Claude tier at $1/$5.
Its trade-offs are real: smallest context in the family (200K), and not for deep reasoning. At $1 in / $5 out per million tokens, it sits in the budget price band.
GPT-6.1 Terra: where it fits
OpenAI's October 26, 2026 mid-tier model - a 1.05M-context, computer-use-capable GPT at $1/$5 per million tokens, half the price of its predecessor. Released October 26, 2026 by OpenAI, it is built for $1/$5 per million tokens (cached input $0.05) - half the price of GPT-6.1 Sol and GPT-5.6 Terra, terminal-Bench 4.0 of 50.3% at maximum reasoning effort, versus 21.5% for GPT-5.6 Terra (OpenAI-reported), 1.05M-token context with up to 128K output tokens, plus image input and computer use via the Responses API, and error rate on OpenAI's hard-prompt set falls from 53.6% (GPT-5.6 Terra) to 16.7% at low effort and 4.3% at max effort.
Its trade-offs: openAI still positions Sol and Astra as the higher-capability choices for demanding coding problems, requests above 272K input tokens are billed at 2x input and 1.5x output for the whole request, closed weights and no fine-tuning support, and benchmark figures are vendor-reported; no SWE-bench Verified or MRCR numbers published. At $1 in / $5 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Claude Haiku 4.5 and GPT-6.1 Terra overlap enough that the right pick depends on your specific job. GPT-6.1 Terra holds the larger context; and each leads in its own area — Claude Haiku 4.5 for fastest claude model, GPT-6.1 Terra for $1/$5 per million tokens (cached input $0.05) - half the price of gpt-6.1 sol and gpt-5.6 terra. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Claude Haiku 4.5 and GPT-6.1 Terra without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
See pricingFrequently asked questions
Is Claude Haiku 4.5 or GPT-6.1 Terra better for coding?
Public SWE-Bench figures are not available for GPT-6.1 Terra, so the honest test is your own repository — run an identical real bug through both. By design, Claude Haiku 4.5 leans toward fastest claude model while GPT-6.1 Terra leans toward $1/$5 per million tokens (cached input $0.05) - half the price of gpt-6.1 sol and gpt-5.6 terra, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Haiku 4.5 or GPT-6.1 Terra?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
GPT-6.1 Terra — 1.05M tokens vs 200K, about 5.3× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Claude Haiku 4.5 and GPT-6.1 Terra together?
Yes — a multi-model platform like LumiChats gives you Claude Haiku 4.5, GPT-6.1 Terra and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Haiku 4.5 or GPT-6.1 Terra?
GPT-6.1 Terra — released October 26, 2026, about 13 months after Claude Haiku 4.5.
Related comparisons
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.