GPT-6 Sol vs Luna
GPT-6 Sol vs GPT-6 Luna
Overview
OpenAI’s GPT-6 mid and low tiers. Sol is the $2 / $10 workhorse (same sticker as Claude Sonnet 5.5). Luna is $0.10 / $0.50 for high-volume, focused jobs—about 1/20 of Sol on input. Astra stays the $10 / $50 flagship. API names: `gpt-6-sol` / `gpt-6.1-sol` and `gpt-6-luna` (confirm the snapshot your host bills).
Standard short context (per million tokens)
| GPT-6 Sol | GPT-6 Luna | |
|---|---|---|
| Input / output | $2 / $10 | $0.10 / $0.50 |
| Cached input | $0.10–$0.20 class* | $0.01 |
| Cache write | ~1.25× input | $0.125 |
| Role | Default GPT-6 work | High-volume / simple |
| >272K input | 2× in/cache, 1.5× out | Same long-context rule |
Capabilities
- Sol — GPT-6 daily driverCoding and professional work that used to sit on GPT-5.6 Sol, now at half that promo price ($4/$20 → $2/$10 per OpenAI’s launch note).
- Luna — cheap loopsClassification, extraction, short codegen, high QPS. Don’t use it as your only model for ambiguous architecture.
- RouterLuna first, Sol if Luna is weak, Astra once if both fail.
Context Window
Both follow OpenAI’s GPT-6 long-context surcharge: prompts over 272K input tokens reprice the full request (2× input/cache, 1.5× output).
- Stay under 272K unless you budget for it.
- Luna at long-context rates is still cheap vs Sol; Sol at long-context is $4 / $15 class.
Pricing
OpenAI standard (short context). Pricing tables also list gpt-6.1-sol at $2 / $10. Batch/Flex 50% off; Fast mode 2×. Regional/FedRAMP uplifts may apply.
- GPT-6 Sol
- $2 in / $10 out · cached in ~$0.10–$0.20 · write ~$2.50
- GPT-6 Luna
- $0.10 in / $0.50 out · cached in $0.01 · write $0.125
- 50K in + 2K out
- Sol ≈ $0.12 · Luna ≈ $0.006
- *OpenAI’s public tables show gpt-6.1-sol cached input at $0.10 and cache writes at $2.50; confirm the exact snapshot id on your invoice.
- Sol vs Luna is ~20× on input. A chatty agent on Sol can cost more than a tight Luna pipeline.
How to Use
- Default Sol for product workFeatures, refactors, multi-file edits.
- Default Luna for volumeEval sets, ingest, and cheap tool loops.
- Watch Fast mode2× on either SKU. Don’t leave it on for Luna batch jobs.