Processing or generating 500,000 words (approximately 640,000 tokens) with GPT-5.4 nano ranges from $0.0128 (cached input) to $0.80 (full generation).
You send 500,000 words as prompt context, documentation, or background knowledge.
GPT-5.4 nano drafts a complete 500,000 words article, chapter, or code module.
400,000 words input prompt + 100,000 words output reply.
| Model | Provider | Input Cost (500,000 words) | Cached Input Cost | Output Cost (500,000 words) | Context Limit |
|---|---|---|---|---|---|
| GPT-5.4 nano (Current) | openai | $0.128 | $0.0128 | $0.80 | 128,000 |
| GPT-5.6 Luna | openai | $0.128 | $0.0128 | $0.768 | 1,050,000 |
| GPT-5.4 mini | openai | $0.48 | $0.048 | $2.88 | 256,000 |
| GPT-4o mini | openai | $0.096 | $0.048 | $0.384 | 128,000 |
| Claude Haiku 4.5 | anthropic | $0.66 | $0.066 | $3.30 | 1,000,000 |
| Claude 3.5 Haiku | anthropic | $0.528 | $0.0528 | $2.64 | 200,000 |
For GPT-5.4 nano (o200k_base tokenizer), 500,000 words is approximately 640,000 tokens (an average ratio of 1.28 tokens per word in English). Code, technical vocabulary, and non-English scripts will have higher token densities.
Sending 500,000 words as input costs $0.128 (or $0.0128 with prompt caching). Generating 500,000 words as output costs $0.80. Output tokens are more expensive because autoregressive token generation requires significantly more computation per token.
Yes! If your input text is part of a repeated context, prompt caching saves 50% to 90% (costing $0.0128). For non-urgent asynchronous batch processing, 24-hour batch queues provide a flat 50% discount across all tokens (costing $0.064 for input, $0.40 for output).
At an average human reading speed of 250 words per minute, 500,000 words takes approximately 2000 minutes to read. In contrast, GPT-5.4 nano can process or generate this text in seconds.