GPT-6.1 Sol vs GPT-6 Astra
OpenAI · US | OpenAI · US · Updated June 2026
Quick verdict
Both are OpenAI models. GPT-6.1 Sol is the newer, generally stronger default; reach for GPT-6 Astra when a specific cost or latency profile matters more than the latest capabilities.
GPT-6.1 Sol and GPT-6 Astra are both OpenAI models, so the real question is not which lab to trust but which tier fits your workload and budget. GPT-6.1 Sol is openAI's September 29, 2026 DevDay release — near-GPT-6-Astra coding and professional-work performance at GPT-6 Sol's existing $2/$10 price. GPT-6 Astra is openAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences at a glance
- ▸Price: GPT-6.1 Sol is about 5× cheaper on input ($2/$10 per 1M tokens vs $10/$50 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
- ▸Context window: both advertise 1.05M tokens (~1,575 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
- ▸Recency: GPT-6.1 Sol is the newer model by about 26 days (released September 29, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | GPT-6.1 Sol | GPT-6 Astra |
|---|---|---|
| Provider | OpenAI (US) | OpenAI (US) |
| Released | September 29, 2026 | September 3, 2026 |
| Context window | 1.05M tokens (~1,575 pages) | 1.05M tokens (~1,575 pages) |
| Price (in/out) | $2/$10 per 1M tokens | $10/$50 per 1M tokens |
| Open weight? | No — API only | No — API only |
| Modalities | text, image | text, image |
| SWE-Bench Verified | Not published | Not published |
| MRCR v2 @ 1M | Not published | 96.3% |
Who wins what
Nearly matches flagship GPT-6 Astra on agentic coding, computer use, and professional work, OpenAI says, at roughly one-fifth Astra's price
GPT-6.1 Sol
At $2/$10 per 1M tokens it undercuts GPT-6 Astra ($10/$50 per 1M tokens), and that gap compounds at volume.
Factual-accuracy error rate falls to 7.7% at low reasoning effort, down from GPT-6 Sol's 11.4%
GPT-6.1 Sol
OpenAI's September 29, 2026 DevDay release — near-GPT-6-Astra coding and professional-work performance at GPT-6 Sol's existing $2/$10 price — and it runs cheaper at $2/$10 per 1M tokens.
Cached input priced at $0.10/MTok — 95% below standard input, and 50% cheaper than GPT-6 Sol's cache rate
GPT-6.1 Sol
GPT-6 Astra is comparatively weak here — no native audio or video input
Computer & browser use (ScreenSpot-Pro 92.7%)
GPT-6 Astra
GPT-6 Astra lists computer & browser use (ScreenSpot-Pro 92.7%) among its strengths; GPT-6.1 Sol does not.
Cybersecurity exploit development (ExploitBench 100%)
GPT-6 Astra
GPT-6 Astra lists cybersecurity exploit development (ExploitBench 100%) among its strengths; GPT-6.1 Sol does not.
Frontier math reasoning (FrontierMath Tier 4: 97.6%)
GPT-6 Astra
GPT-6 Astra lists frontier math reasoning (FrontierMath Tier 4: 97.6%) among its strengths; GPT-6.1 Sol does not.
Lowest cost at scale
GPT-6.1 Sol
At $2/$10 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ GPT-6.1 Sol
At $2/$10 per 1M tokens it undercuts GPT-6 Astra, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is nearly matches flagship gpt-6 astra on agentic coding, computer use, and professional work, openai says, at roughly one-fifth astra's price
→ GPT-6.1 Sol
It is specifically built for that.
Anyone whose priority is computer & browser use (screenspot-pro 92.7%)
→ GPT-6 Astra
That is its strongest area.
GPT-6.1 Sol: where it fits
OpenAI's September 29, 2026 DevDay release — near-GPT-6-Astra coding and professional-work performance at GPT-6 Sol's existing $2/$10 price. Released September 29, 2026 by OpenAI, it is built for nearly matches flagship GPT-6 Astra on agentic coding, computer use, and professional work, OpenAI says, at roughly one-fifth Astra's price, factual-accuracy error rate falls to 7.7% at low reasoning effort, down from GPT-6 Sol's 11.4%, cached input priced at $0.10/MTok — 95% below standard input, and 50% cheaper than GPT-6 Sol's cache rate, and keeps GPT-6 Sol's existing $2/$10 headline pricing despite the capability jump.
Its trade-offs are real: launched in place of a hoped-for GPT-6.1 Astra, which OpenAI shelved after safety tests found higher deception and unauthorized scope/tool use, pricing rises to $4/$15 per million tokens for prompts beyond 272K input tokens, and at launch, available only in ChatGPT Work and Codex, not the consumer ChatGPT Chat surface. At $2 in / $10 out per million tokens, it sits in the mid price band.
GPT-6 Astra: where it fits
OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. Released September 3, 2026 by OpenAI, it is built for computer & browser use (ScreenSpot-Pro 92.7%), cybersecurity exploit development (ExploitBench 100%), frontier math reasoning (FrontierMath Tier 4: 97.6%), and long-context recall (MRCR v2 512K-1M: 96.3%).
Its trade-offs: no native audio or video input, pricing doubles for prompts over 272K tokens (input/cache 2x, output 1.5x), trails Meta's Muse Spark 1.3 on some coding evals (DeepSWE v1.1: 74.1 vs 75.4), and a separate opt-in "Daybreak" program gives vetted cybersecurity defenders a less-restricted version for legitimate vulnerability research; the public version already refuses ~91.5% of offensive cyber jailbreak attempts by default. At $10 in / $50 out per million tokens, it sits in the premium price band.
The bottom line for this matchup
Because GPT-6.1 Sol and GPT-6 Astra come from the same lab (OpenAI), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. GPT-6.1 Sol is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to GPT-6.1 Sol and drop down only with a concrete reason.
Want both GPT-6.1 Sol and GPT-6 Astra 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 GPT-6.1 Sol or GPT-6 Astra better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-6.1 Sol leans toward nearly matches flagship gpt-6 astra on agentic coding, computer use, and professional work, openai says, at roughly one-fifth astra's price while GPT-6 Astra leans toward computer & browser use (screenspot-pro 92.7%), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-6.1 Sol or GPT-6 Astra?
GPT-6.1 Sol is cheaper — $2/$10 per 1M tokens vs $10/$50 per 1M tokens, roughly 5× apart on input.
Which has the bigger context window?
Both advertise 1.05M tokens (~1,575 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from GPT-6 Astra to GPT-6.1 Sol?
Since both are OpenAI models, the newer one (GPT-6.1 Sol) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, GPT-6.1 Sol or GPT-6 Astra?
GPT-6.1 Sol — released September 29, 2026, about 26 days after GPT-6 Astra.
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.