AI Models · Open-Source vs Paid

LFM2.5-2.6B Open vs GPT-6 Sol Pro Paid

LFM2.5-2.6B vs GPT-6 Sol Pro compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

LFM2.5-2.6BOpenLiquid
$0.35 /M input
$0.5 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window128K tokens
MultimodalNo
Self-hostYes
GPT-6 Sol ProPaidOpenAI
$2 /M input
$10 /M outputManaged API (no infra to run)
TypeProprietary
Context window1.1M tokens
MultimodalYes
Self-hostNo
Choose LFM2.5-2.6B if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-6 Sol Pro if you want frontier capability through a managed API with zero infrastructure to run.

LFM2.5-2.6B vs GPT-6 Sol Pro specs

SpecLFM2.5-2.6BGPT-6 Sol ProWinner
MakerLiquidOpenAI–
TypeOpen-weightProprietaryLFM2.5-2.6B
Context window128K tokens1.1M tokensGPT-6 Sol Pro
Input price$0.35/M · free self-host$2/MLFM2.5-2.6B
Output price$0.5/M · free self-host$10/MLFM2.5-2.6B
Vision / multimodalNoYesGPT-6 Sol Pro
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)LFM2.5-2.6B
LicenseOpen weightsProprietaryLFM2.5-2.6B

Price gap & when to choose each

20×cheaper per output token

LFM2.5-2.6B is ~20× cheaper than GPT-6 Sol Pro on output tokens ($0.5 vs $10 per M tokens).

Choose LFM2.5-2.6B if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose GPT-6 Sol Pro if…
  • You want frontier performance through a managed API
  • You need the longer 1.1M context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityLFM2.5-2.6BGPT-6 Sol Pro
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✗✓
Tool / function calling✓✓
1M+ context window✗✓

Benchmarks: LFM2.5-2.6B vs GPT-6 Sol Pro

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

LFM2.5-2.6B
GPT-6 Sol Pro
Intelligence index
8.4
–
Coding index
7.7
–
GPQA
55.8%
–
Humanity's Last Exam
6.2%
–
Long Context Reasoning
5.7%
–
SciCode
14.4%
–
τ-Bench Banking
7.2%
–
Terminal-Bench
4.5%
–
Speed
0 tok/s
–
Latency
0s
–

Benchmark data by Artificial Analysis.

How LFM2.5-2.6B and GPT-6 Sol Pro score

🏆 Best value & openness: LFM2.5-2.6B (4.4 vs 3.2 / 5)
CriterionLFM2.5-2.6BGPT-6 Sol Pro
Cost-efficiency5.03.5
Context window3.55.0
Openness5.01.5
Self-hosting5.01.0
Multimodality3.55.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

LFM2.5-2.6B Open

Liquid · Open-weight

LFM2.5-2.6B is a compact reasoning model from Liquid AI. It is suited for agent workflows, data extraction, RAG, and long-context processing. Liquid advises against using it for agentic coding or...

GPT-6 Sol Pro Paid

OpenAI · Proprietary

GPT-6 Sol Pro is the same underlying model as [GPT-6 Sol](https://openrouter.ai/openai/gpt-6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. **Cost note:** pro mode spends far more...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
LFM2.5-2.6B (free)LFM2.5-24B-A2B

Frequently asked questions

Is LFM2.5-2.6B as good as GPT-6 Sol Pro?

LFM2.5-2.6B is open-weight and competitive on many tasks, but GPT-6 Sol Pro may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run LFM2.5-2.6B locally?

Yes. LFM2.5-2.6B has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-6 Sol Pro is API-only and cannot be self-hosted.

How much cheaper is LFM2.5-2.6B?

LFM2.5-2.6B costs $0.5/M output vs $10/M for GPT-6 Sol Pro — roughly 20x cheaper via API, and free if you self-host.

LFM2.5-2.6B vs GPT-6 Sol Pro — which should I pick in 2026?

Choose LFM2.5-2.6B if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-6 Sol Pro if you want frontier capability through a managed API with zero infrastructure to run.

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