# GPT-6 Luna (default medium reasoning effort) vs jeff (Logan Markewich, GLiFormer 400M)

> Side-by-side benchmark comparison for GPT-6 Luna (default medium reasoning effort) and jeff (Logan Markewich, GLiFormer 400M) across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/jevbench-gpt-6-luna-vs-jevbench-jeff
- Last updated: September 30, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: GPT-6 Luna (default medium reasoning effort) and jeff (Logan Markewich, GLiFormer 400M) share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.

## Model Snapshot

| Property | GPT-6 Luna (default medium reasoning effort) | jeff (Logan Markewich, GLiFormer 400M) |
|----------|----------|----------|
| Creator | OpenAI | Logan Markewich |
| Type | Unknown | Open Weight |
| Reasoning | Reasoning | Non-Reasoning |
| Context | null | null |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 2 | 2 |
| Pricing (input/output) | Pricing unavailable / Pricing unavailable | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Reasoning

- Winner: Insufficient shared evidence
- GPT-6 Luna (default medium reasoning effort) public-lane score: Coming soon
- jeff (Logan Markewich, GLiFormer 400M) public-lane score: Coming soon

| Benchmark | GPT-6 Luna (default medium reasoning effort) | jeff (Logan Markewich, GLiFormer 400M) | Winner |
|-----------|-----------|-----------|--------|
| JevBench 1.4 | 33.27 | 30.58 | GPT-6 Luna (default medium reasoning effort) |
| JevBench 1.5 | 38.75 | 0.12 | GPT-6 Luna (default medium reasoning effort) |

## FAQ

### Is there enough evidence to pick between GPT-6 Luna (default medium reasoning effort) and jeff (Logan Markewich, GLiFormer 400M)?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [GPT-6 Luna (default medium reasoning effort) vs GPT-6 Astra](/compare/gpt-6-astra-vs-jevbench-gpt-6-luna)
- [jeff (Logan Markewich, GLiFormer 400M) vs GPT-6 Astra](/compare/gpt-6-astra-vs-jevbench-jeff)
- [GPT-6 Luna (default medium reasoning effort) vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-jevbench-gpt-6-luna)
- [jeff (Logan Markewich, GLiFormer 400M) vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-jevbench-jeff)

## Explore More

- [GPT-6 Luna (default medium reasoning effort) profile](/models/jevbench-gpt-6-luna)
- [jeff (Logan Markewich, GLiFormer 400M) profile](/models/jevbench-jeff)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)