OpenAI Releases GPT-5.5: Faster, Smarter—And Pricier

Image: OpenAI

It’s also a pretty good coder, as expected. On Expert-SWE, an internal benchmark for long-horizon coding tasks with a median estimated human completion time of 20 hours, GPT-5.5 outperforms GPT-5.4. On SWE-Bench Pro, which grades real-world GitHub issue resolution, it reaches 58.6%. Claude Opus 4.7 scores higher at 64.3%, but OpenAI claims it may be because “Anthropic reported⁠ signs of memorization on a subset of problems”

This launch lands in a market that is moving rapidly since the boom of agentic AI. GPT-5.4 arrived just two days after GPT-5.3, while Xiaomi went from MiMo-V2-Pro to MiMo 2.5 Pro—with full multimodal capabilities—in roughly five weeks. The gap between GPT-5.4 and GPT-5.5 was about seven weeks. That's the tempo now.

But will this model make a difference for everyday users who are not always coding the next big thing? If you're on a free tier, no: GPT-5.5 isn't coming to free users. If you're paying for Plus at $20/month, it rolls out today. We tried testing it under our Pro account, but the model was not immediately available.

The bigger deal is probably what GPT-5.5 does inside Codex—OpenAI's agentic coding environment—where it is proven to be more powerful. “It genuinely feels like I’m working with a higher intelligence, and there’s almost a sense of respect,” Pietro Schirano, CEO of MagicPath, said in a quote shared by OpenAI.

GPT-5.5 Pro, designed for harder, higher-accuracy work, is rolling out separately to Pro, Business, and Enterprise users in ChatGPT. On BrowseComp, which tests a model's ability to track down hard-to-find information across the web, GPT-5.5 Pro scores 90.1%, ahead of Gemini 3.1 Pro at 85.9%.

The model is also the most intelligent on average based on the Artificial Analysis Index. GPT 5.5 reports a more efficient and useful use of tokens, producing better results in general.

Image: OpenAI

The pricing, however, could shock some users. The API will charge $5 per million input tokens and $30 per million output tokens when it launches, which OpenAI says is coming "very soon." GPT-5.5 Pro in the API will cost $30 per million input tokens and $180 per million output tokens.

Those figures are higher than GPT-5.4—$2.50 per million tokens of input and $15.00 per million tokens of output—while pricing for GPT-5.5 Pro remains the same as GPT-5.4 Pro.

That said, OpenAI CEO Sam Altman argued on X that token efficiency gains offset the cost—GPT-5.5 completes the same Codex tasks with fewer tokens, which means cheaper runs even at a higher per-token rate.

Just for comparison, Xiaomi MiMo v2.5 Pro charges $1 and $3 per million tokens of input and output, Minimax M2.7 costs $0.30 and $1.20 respectively, and Kimi K2.5 requires $0.44 and $2.00 per million tokens.