Open-source and open-weight ChatGPT alternatives ranked by benchmark performance, coding strength, and deployment flexibility.
Open source ChatGPT alternative queries are a better fit for BenchLM than generic chatbot roundups because the real decision is not just interface parity. It is which self-hostable models still hold up on coding, reasoning, and research benchmarks.
BenchLM uses GPT-5.5 as the tracked OpenAI reference for ChatGPT-like performance.
Direct answer
GLM-5.2 is a strong ChatGPT alternative. It retains about 99% of GPT-5.5's general use benchmark profile. Its blended token price is about 84% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
Z.AI · Open Weight · 1M context
GLM-5.2 is a strong ChatGPT alternative. It retains about 99% of GPT-5.5's general use benchmark profile. Its blended token price is about 84% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
90.8
Score vs ref
99%
Token cost
84% cheaper
DeepSeek · Open Weight · 1M context
DeepSeek V4 Pro (Max) is a strong ChatGPT alternative. It retains about 91% of GPT-5.5's general use benchmark profile. Its blended token price is about 97% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
88.8
Score vs ref
91%
Token cost
97% cheaper
MiniMax · Open Weight · 1M context
MiniMax M3 is a strong ChatGPT alternative. It still posts a credible 61 score for general use work on BenchLM. Its blended token price is about 96% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
86
Score vs ref
82%
Token cost
96% cheaper
Poolside · Open Weight · 1M context
Laguna S 2.1 is a strong ChatGPT alternative. It still posts a credible 60 score for general use work on BenchLM. Its blended token price is about 99% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
85.7
Score vs ref
~81%
Token cost
99% cheaper
DeepReinforce AI · Open Weight · 256K context
Ornith-1.0-397B is a strong ChatGPT alternative. It retains about 95% of GPT-5.5's general use benchmark profile. Its blended token price is about 100% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
85.6
Score vs ref
~95%
Token cost
100% cheaper
Thinking Machines Lab · Open Weight · 1M context
Inkling is a strong ChatGPT alternative. It still posts a credible 62 score for general use work on BenchLM. Its blended token price is about 83% lower than GPT-5.5. It is also open-weight, so you can self-host or fine-tune it.
BenchLM fit
85.6
Score vs ref
84%
Token cost
83% cheaper
BenchLM does not treat an alternative query like a generic leaderboard. This page starts from the tracked GPT-5.5 reference, then weights benchmark quality, token cost, context window, and deployment model to find realistic replacements.
That means a model can outrank the absolute leaderboard leader here if it stays close enough on benchmarks while being materially cheaper, more open, or better matched to the workflow implied by the query.
Change the goal, use case, or minimum context if this landing page is close but not exact.
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GLM-5.2 is the current top pick on this page. It scores 73 in the selected BenchLM use-case weighting and 99% of GPT-5.5's benchmark profile, with 84% cheaper as the pricing summary.
Ornith-1.0-397B is the best low-cost candidate surfaced by this page. It ranks as a serious replacement while landing at 100% cheaper than the tracked GPT-5.5 reference.
Yes. GLM-5.2 is the strongest open-weight option on this page. BenchLM surfaces it because it combines self-hostable deployment with a 73 weighted score and 1M of context.
BenchLM uses GPT-5.5 as the tracked ChatGPT reference here, then scores alternatives from benchmark performance first. Token cost, context window, and open-weight preference are used to break ties and surface better real-world replacements rather than just the raw leaderboard winner.