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OpenAI releases GPT-6 Sol and Luna at half the cost

OpenAI releases GPT-6 Sol and Luna at half the cost
Photo: Mikhail Nilov / Pexels

OpenAI released GPT-6 Sol and GPT-6 Luna on September 22, 2026, two models trained with methods similar to its flagship GPT-6 Astra but priced at roughly half their GPT-5.6 equivalents. Sol costs $2 per million input tokens and $10 per million output tokens; Luna costs $0.10 and $0.50. On AutomationBench, a test of end-to-end business workflows across 47 tools, Sol at maximum effort outperforms Claude Opus 5 at just 9% of its per-task cost. The releases let companies revisit automation workflows previously too expensive to justify at scale.

In short

  • OpenAI released GPT-6 Sol and Luna on September 22 at 50% lower prices than their predecessors, with Sol at $2/$10 and Luna at $0.10/$0.50 per million tokens
  • On AutomationBench business workflows, Sol outperforms Claude Opus 5 at just 9% of its per-task cost, shifting economics for operations automation
  • Both models hallucinate less than predecessors and improve on coding benchmarks, making them suitable for document processing and agentic workflows
  • Lower model costs now let companies automate full-scale volumes rather than samples, removing cost bottlenecks from existing operational workflows
  • Anthropic released Claude Opus 5.5 the same day with similar cost-and-speed positioning, signaling a shift toward tiered pricing across frontier labs

Two new models bring frontier-level performance to high-volume automation

OpenAI released GPT-6 Sol and GPT-6 Luna on September 22, 2026. According to OpenAI, both models were trained with methods similar to GPT-6 Astra but optimized for speed and cost. GPT-6 Sol targets complex work tasks including coding and business automation. GPT-6 Luna is designed for high-volume, well-defined tasks that run repeatedly.

Pricing cuts are substantial. GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens, down 50% from the previous GPT-5.6 promotional pricing. GPT-6 Luna costs $0.10 and $0.50, also 50% lower. Both models carry a 1.05-million-token context window and support text and image input.

Practical implications for operations work

The release shifts how teams evaluate automation economics. According to benchmark testing by OpenAI, on AutomationBench—which evaluates agents completing workflows across 47 business tools in sales, marketing, operations, support, finance and HR—GPT-6 Sol at maximum effort scores 33.2% at $0.27 per task. This outperforms Claude Opus 5 at its maximum effort setting at just 9% of the per-task cost.

Teams running document classification, content summarization, ticket routing, campaign analysis or agentic workflows can now revisit tasks that were previously too expensive to automate at full scale. A customer support team might now run quality checks on every incoming ticket rather than a sample. An operations team might analyze every account instead of only high-value ones.

However, lower model cost alone does not guarantee a worthwhile automation. Human review, API calls to other systems, storage, logging and failure handling still cost time and money. The stronger business case appears when lower model cost removes a real bottleneck from an already useful workflow.

Competitive positioning and what to expect next

Anthropic released Claude Opus 5.5 on the same day as OpenAI's announcement, with similar positioning: same training methods as the flagship, optimized for cost and speed. On Artificial Analysis benchmarks, GPT-6 Sol and Luna both show improvements in hallucination rates. According to the hallucination benchmark AA-Omniscience, Sol reduces its hallucination rate from 92% to 60% and Luna from 93% to 77%.

The releases reflect a shift in frontier model economics. For the past year, pricing followed a simple pattern: better capability meant higher cost. GPT-6 Sol and Luna demonstrate that capability and cost can move independently. This likely signals that other labs will continue releasing lower-cost tiers built on existing architectures.

Teams should begin auditing their existing workflows to identify which could now run at scale. A 50% cost reduction on high-volume tasks can change which automation projects clear a business case, especially for mid-size companies processing thousands of documents, tickets or customer interactions monthly.

How AiStaffo would automate this

AiStaffo automates back-office staff work using AI: data entry, follow-ups, reconciliations, reports, billing and document handling. The release of GPT-6 Sol and Luna at half the cost makes it practical to run document classification, ticket routing, invoice processing and account reconciliation on every single item in a queue, not just high-value ones. AiStaffo connects these models to your business systems—your CRM, accounting software, ticketing platform—to run automations that previously required sample-based review or human-touch checkpoints. Sol handles complex multi-step workflows like invoice validation or complaint triage; Luna processes high-volume repetitive work like field extraction or status updates. The owner still reviews exceptions and sets policy; everything else runs automatically. Book a free automation audit to identify which staff workflows AiStaffo can transfer to these new models.

Questions people ask

How much cheaper are GPT-6 Sol and Luna than the previous versions?
Both models cost roughly 50% less per token than their GPT-5.6 predecessors. GPT-6 Sol dropped from $4/$20 to $2/$10 per million input/output tokens. Luna fell from $0.20/$1.20 to $0.10/$0.50. The 50% reduction applies across both input and output pricing.
Which model should we use for our automation workflows?
GPT-6 Sol is designed for complex tasks like coding, agentic workflows and multi-step business processes. Luna is better for high-volume, well-defined tasks that repeat thousands of times, such as ticket categorization or field extraction. On AutomationBench, Sol outperformed competitors on workflows across sales, marketing, operations, support, finance and HR.
How does Sol compare to Claude models?
According to OpenAI benchmarks, GPT-6 Sol at maximum effort outperforms Claude Opus 5 at its maximum effort on AutomationBench at just 9% of the per-task cost. Independent benchmarking by Artificial Analysis shows mixed results: Sol improves on automation workflows but lags slightly on pure coding and knowledge work compared to Claude Fable 5.1.
Do these models work with the tools our team already uses?
Yes. Both Sol and Luna support function calling, web search, file search and computer use. They accept text and image input and return text output. They integrate with the OpenAI API and are available through any platform that supports OpenAI's API, including most workflow automation tools.
When should a company switch to these models?
Start by auditing workflows that currently run on cheaper or older models, or workflows that are only automated on a sample basis due to cost. If your team manually processes 1000+ documents, tickets or records per month, the cost savings from Sol or Luna may now justify full-scale automation rather than spot-checking or human review.

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