About GPT-5
GPT-5 is the model that unified OpenAI's two earlier lines — the GPT series and the o-series reasoning models — into one system with adjustable reasoning effort. OpenAI introduced it as its flagship for coding, agentic tasks and professional writing, and made it the default model behind ChatGPT on release.
It reads text and images, writes text, and scales its reasoning from minimal for quick lookups to high for long deliberate problem-solving, so one model covers both ends. The mini and nano variants share its interface at smaller sizes, making the family a common default for production API work.
GPT-5's pricing made frontier reasoning unusually accessible: input is cheap for the tier, with cost concentrated in output tokens — budget by expected response length, not prompt size, and remember that high reasoning effort spends extra output-priced tokens invisibly. Prompt caching takes an order of magnitude off repeated input, and batch requests earn a further discount when results can wait. The practical comparison points are its own siblings: mini for well-defined tasks at a fraction of the price, nano for high-volume simple work. Against the newer GPT-5.6 family it holds a value position — lower list rates than Sol, smaller context window.
Frequently asked questions
How much does the GPT-5 API cost?
GPT-5 costs $1.25 per million input tokens and $10 per million output tokens, with cached input at $0.125 per million (90% off).
How much does a typical chat message cost with GPT-5?
A short chat message (about 500 input and 250 output tokens) costs roughly $0.0031 with GPT-5. At 1,000 such requests a day, that is about $93.75 per month.
Is GPT-5 cheap compared to similar models?
GPT-5 has the #15 cheapest input rate of the 29 models we track. On a mixed workload (10K input / 2K output), it costs $0.033 per request, versus $0.030 for Mistral Medium 3.5 and $0.040 for Claude Sonnet 5.
What does GPT-5 cost per 1,000 tokens?
Per 1,000 tokens, GPT-5 costs $0.0013 for input and $0.0100 for output, or $0.00013 for cached input. Providers quote rates per million tokens ($1.25/M in, $10/M out here), so divide by a thousand for the per-1K figure older pricing pages used.
How large a prompt can GPT-5 take?
GPT-5 accepts up to 391K tokens of input context and can generate up to 125K tokens of output per request. At its input rate, filling the entire 391K-token window costs about $0.500 per request before any output.
Related
Compare all models at once ·Count tokens in your prompt · GPT-5 vs Claude Sonnet 5 head-to-head
All OpenAI model costs: GPT-5.6 Sol · GPT-5.6 Terra · GPT-5.6 Luna · GPT-5.4 · GPT-5 mini · GPT-5 nano · GPT-4o · GPT-4o mini · o3 · o4-mini
Last updated 2026-09-03. Prices verified against OpenAI's official pricing page; see the methodology.