CURRENT MODEL COMPARISON / 2026

GPT-6 Sol vs GPT-6 Luna

What do you gain by selecting Sol rather than Luna for the same task?

Reviewed Live model evidence ↗
OpenAI

GPT-6 Sol↗

A September 2026 reasoning model with text and image inputs, introduced alongside GPT-6 Luna.

Access type
Hosted API
Original release date
Model ID
gpt-6-sol
Input / output
Text and image inputs; text output
API formats
Responses and Chat Completions
License / terms
Provider service terms

Distinguish GPT-6 Sol from the later GPT-6.1 Sol release. Pricing depends on input length, caching and processing tier; keep those choices in the evaluation record.

Official source ↗Latest artifacts and release journal →
OpenAI

GPT-6 Luna↗

A September 2026 reasoning model with text and image inputs and text output.

Access type
Hosted API
Original release date
Model ID
gpt-6-luna
Input / output
Text and image inputs; text output
API formats
Responses and Chat Completions; Decisions beta added October 6, 2026
License / terms
Provider service terms

Responses and Chat Completions are supported; the Decisions API was added in beta on October 6, 2026. Evaluate that endpoint separately and recheck prices and token tiers.

Official source ↗Latest artifacts and release journal →

The decision to test

These models launched together September 22, 2026, with text and image inputs. Start with identical tasks, endpoints and reasoning settings; record enough cases to expose retries and wrong answers.

Re-run image cases after the lifecycle update

OpenAI announced an image-encoding fix for both models on September 25, 2026. Results from before that fix are a distinct evaluation snapshot. Use the same image resolution, preprocessing and ground truth in a new test.

Keep input length and processing tier explicit

The launch pricing examples were scoped to prompts up to 272K input tokens. Caching, longer prompts and other tiers can change the estimate. Build the bill from actual token usage and the selected rate.

Three criteria for this comparison

  1. Correct answers on identical labeled cases
  2. Image-task behavior after the September 25 fix
  3. Total accepted-result cost at fixed output budgets

Run a fair comparison

Use the same representative inputs and a written answer rubric. Pin the model version and record the endpoint, thinking configuration, quantization when known, context length, output allowance and concurrency. Preserve native request differences in an adapter rather than silently dropping fields.

Measure full request time, error rate and reported usage. For tools, validate arguments and score the result after execution. For images, preserve resolution and preprocessing. A valid response format alone does not establish a correct answer.

Compare cost per accepted result

Calculate input cost plus all billed output, including reasoning where the provider counts it. Add retries and discarded answers. Divide the total by the number of results that pass your quality criteria. Keep API usage cost separate from deployment and engineering cost.

Estimate token costs with the API calculator →

Independent benchmark evidence

Open the full live comparison →
Latest recorded measurements aligned by exact artifact, benchmark version, source and methodology. These are source results, not tests of Flonno's deployment.
Benchmark / sourceGPT-6 SolGPT-6 Luna
Artificial Analysis Intelligence Indexv4.3 · Artificial Analysis47.6 index_pointsMeasured Oct 1, 2026Original result ↗38.1 index_pointsMeasured Oct 1, 2026Original result ↗

Artificial Analysis observations are refreshed by the integrated Radar. Differences in artifact, benchmark version or method prevent a score comparison. Read the evidence methodology →

YOUR WORKLOAD

Compare cost per accepted task.

Enter results from your own evaluation. A task should count once it meets your written quality criteria. Include failed attempts and retries in total spend. These inputs stay in this browser and are not a Flonno benchmark.

GPT-6 Sol
GPT-6 Luna
GPT-6 Sol

Enter all four values. Attempted tasks must be at least one; accepted tasks cannot exceed attempted tasks.

GPT-6 Luna

Enter all four values. Attempted tasks must be at least one; accepted tasks cannot exceed attempted tasks.

Turn evidence into a deployment decision

A source benchmark can inform your shortlist, while your evaluation shows whether a model finishes the work at an acceptable cost. Keep the chosen endpoint, processing terms and output limits in the decision record. Inclusion in the Radar does not mean the model is served by Flonno.

For the API currently offered here, explore Qwen3.8 Flash 27B and the production evaluation guide.

Related current comparisons

Browse current guides →