GPT-4o-mini (OpenAI) and GPT-6 Astra (OpenAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 9 September 2026
As of 9 September 2026, GPT-6 Astra holds the stronger ModelCap Index position (#1 vs #117); GPT-4o-mini is 83.3× cheaper per output token ($0.60/1M vs $50.00/1M); and GPT-6 Astra offers the longer context window (1M vs 128K tokens).
Evidence: publisher-corpus-prior over 182 held-out anchors (61%); 1 specialist-board observation at 2.1% support (40%); shrunk 22.1 up toward the measured corpus · 4 public benchmark observations across 4 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Benchmark scores: GPT-4o-mini vs GPT-6 Astra
Public benchmark boards where GPT-4o-mini or GPT-6 Astra has a published result
GPT-6 Astra ranks higher on the ModelCap Index as of 9 September 2026: #1 against #117. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals do not overlap, but the aggregate Index does not predict performance on every task; compare the relevant benchmark configurations before choosing.
Is GPT-4o-mini cheaper than GPT-6 Astra?
GPT-4o-mini is cheaper on output tokens: $0.60/1M against $50.00/1M. Input tokens are $0.15/1M for GPT-4o-mini and $10.00/1M for GPT-6 Astra. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $0.60 for GPT-4o-mini versus $45.00 for GPT-6 Astra. GPT-4o-mini costs 98.7% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.
Which has the bigger context window, GPT-4o-mini or GPT-6 Astra?
GPT-6 Astra has the larger context window: 1M tokens against 128K.
Which is better for coding, GPT-4o-mini or GPT-6 Astra?
Are GPT-4o-mini and GPT-6 Astra open-weight models?
GPT-4o-mini: API only. GPT-6 Astra: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
Where can I run GPT-4o-mini and GPT-6 Astra?
ModelCap currently lists 2 API providers for GPT-4o-mini and 2 for GPT-6 Astra, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
How current is this GPT-4o-mini vs GPT-6 Astra comparison?
Every figure comes from the sealed ModelCap dataset published 9 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.