Standard Compute
Model comparison 2026

GPT-5.6 Luna vs GPT-6.1 Sol

GPT-5.6 Luna
OpenAI · Budget · Proprietary
$0.50/1M · 1.1M ctx
GPT-6.1 Sol
OpenAI · Balanced · Proprietary
$4.40/1M · 1.1M ctx

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality
Correctness and depth of what it produces
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for money
How much capability you get per dollar
Reliability
Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec
GPT-5.6 Luna
GPT-6.1 Sol
Maker
OpenAI
OpenAI
Blended price / 1M
$0.50
$4.40
Input / output
$0.20 in · $1.20 out / 1M tokens
$2.00 in · $10 out / 1M tokens
Context window
1.1M
1.1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
8.4
9.6
Agentic Ability
8.3
9.7
Speed
9.3
7.0
Value for money
9.0
9.0
Reliability
9.1
9.3

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: GPT-5.6 Luna or GPT-6.1 Sol?

Updated 2026-10-13

Choose GPT-5.6 Luna if you want cheap, fast subtasks, routing, and subagents in OpenAI-based stacks. Choose GPT-6.1 Sol if you want the default OpenAI model for coding agents, from routine changes to hard tasks.

In our editorial scoring, GPT-6.1 Sol leads in 3 of five dimensions (output quality, agentic ability and reliability), while GPT-5.6 Luna leads in 1. On price, GPT-5.6 Luna runs about $0.50 per 1M tokens (blended) and is proprietary; GPT-6.1 Sol is about $4.40 and proprietary.

Where GPT-5.6 Luna falls short
  • Clear quality step below Terra and Sol
  • Superseded by GPT-6 Luna, which is cheaper ($0.10/$0.50) and stronger
Full GPT-5.6 Luna breakdown →
Where GPT-6.1 Sol falls short
  • Slower than GPT-6 Sol at max effort (about 65 output tokens/s)
  • Prompts over 272K tokens are billed at higher rates
Full GPT-6.1 Sol breakdown →

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