Claude Haiku 4.5 vs GPT-5.6 Luna
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-5.6 Luna for cheapest gpt-5.6 tier for high-volume drafting and automation or fast, affordable execution while keeping respectable coding.
Claude Haiku 4.5 (Anthropic) and GPT-5.6 Luna (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-5.6 Luna is the budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning. 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-5.6 Luna holds 5× more — 1M (~1,500 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-5.6 Luna is the newer model by about 9 months (released July 9, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Claude Haiku 4.5 | GPT-5.6 Luna |
|---|---|---|
| Provider | Anthropic (US) | OpenAI (US) |
| Released | October 15, 2025 | July 9, 2026 |
| Context window | 200K (~300 pages) | 1M (~1,500 pages) |
| Price (in/out) | $1/$5 per 1M tokens | $1/$6 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-5.6 Luna does not.
Near-frontier coding for its tier — 73.3% on SWE-Bench Verified
Claude Haiku 4.5
Claude Haiku 4.5 lists near-frontier coding for its tier — 73.3% on SWE-Bench Verified among its strengths; GPT-5.6 Luna does not.
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-5.6 Luna does not.
Cheapest GPT-5.6 tier for high-volume drafting and automation
GPT-5.6 Luna
The budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning — and it carries the larger 1M context.
Fast, affordable execution while keeping respectable coding
GPT-5.6 Luna
The budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning — and it is the newer of the two.
Same 1M context and programmatic tool calling as its siblings
GPT-5.6 Luna
Its 1M window holds about 5× more than Claude Haiku 4.5's 200K in a single prompt.
Largest single-prompt input
GPT-5.6 Luna
Its 1M window is about 5× larger than Claude Haiku 4.5's 200K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
Someone analysing very long documents or codebases
→ GPT-5.6 Luna
Larger 1M 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 cheapest gpt-5.6 tier for high-volume drafting and automation
→ GPT-5.6 Luna
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-5.6 Luna: where it fits
The budget, high-throughput GPT-5.6 tier — built for cheap, fast, large-volume work rather than deep long-context reasoning. Released July 9, 2026 by OpenAI, it is built for cheapest GPT-5.6 tier for high-volume drafting and automation, fast, affordable execution while keeping respectable coding, same 1M context and programmatic tool calling as its siblings, and high-throughput simple agentic jobs.
Its trade-offs: weak long-context recall deep in its 1M window (MRCR far below Sol), and lowest raw capability of the three GPT-5.6 tiers; no open weights. At $1 in / $6 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
Claude Haiku 4.5 and GPT-5.6 Luna overlap enough that the right pick depends on your specific job. GPT-5.6 Luna holds the larger context; and each leads in its own area — Claude Haiku 4.5 for fastest claude model, GPT-5.6 Luna for cheapest gpt-5.6 tier for high-volume drafting and automation. 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-5.6 Luna 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-5.6 Luna better for coding?
Public SWE-Bench figures are not available for GPT-5.6 Luna, 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-5.6 Luna leans toward cheapest gpt-5.6 tier for high-volume drafting and automation, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Haiku 4.5 or GPT-5.6 Luna?
They are priced almost identically, so cost will not decide between them.
Which has the bigger context window?
GPT-5.6 Luna — 1M vs 200K, about 5× 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-5.6 Luna together?
Yes — a multi-model platform like LumiChats gives you Claude Haiku 4.5, GPT-5.6 Luna 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-5.6 Luna?
GPT-5.6 Luna — released July 9, 2026, about 9 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.