About GPT-5.4
GPT-5.4 arrived between the original GPT-5 generation and the GPT-5.6 family, described by OpenAI as a more affordable model for coding and professional work. It brought the million-token-class context window to the mainline series, takes text and images in, writes text out, and supports reasoning effort from none up to xhigh.
OpenAI keeps it available alongside the newer family, and its feature set — structured outputs, function calling, file handling, web search, prompt caching — matches what agentic and coding workloads expect.
GPT-5.4 sits close to Terra on list price, which frames the decision: the newer tier offers a fresher knowledge cutoff at similar rates, so new projects usually start there while established GPT-5.4 integrations keep running unchanged. Caching discounts repeated input by an order of magnitude, and the long-prompt multiplier applies once a request crosses OpenAI's threshold — to the whole request, not just the excess. Batch processing is supported for asynchronous work. If cost is the constraint rather than capability, the mini and nano tiers of the main GPT-5 line undercut it substantially.
Frequently asked questions
How much does the GPT-5.4 API cost?
GPT-5.4 costs $2.5 per million input tokens and $15 per million output tokens, with cached input at $0.25 per million (90% off). Note: Prompts over 272K input tokens are billed at 2× input and 1.5× output for the whole request.
How much does a typical chat message cost with GPT-5.4?
A short chat message (about 500 input and 250 output tokens) costs roughly $0.0050 with GPT-5.4. At 1,000 such requests a day, that is about $150.00 per month.
Is GPT-5.4 cheap compared to similar models?
GPT-5.4 has the #23 cheapest input rate of the 29 models we track. On a mixed workload (10K input / 2K output), it costs $0.055 per request, versus $0.033 for Gemini 2.5 Pro.
What does GPT-5.4 cost per 1,000 tokens?
Per 1,000 tokens, GPT-5.4 costs $0.0025 for input and $0.0150 for output, or $0.00025 for cached input. Providers quote rates per million tokens ($2.5/M in, $15/M out here), so divide by a thousand for the per-1K figure older pricing pages used.
How large a prompt can GPT-5.4 take?
GPT-5.4 accepts up to 1025K tokens of input context and can generate up to 125K tokens of output per request. At its input rate, filling the entire 1025K-token window costs about $2.63 per request before any output.
Related
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All OpenAI model costs: GPT-5.6 Sol · GPT-5.6 Terra · GPT-5.6 Luna · GPT-5 · 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.