OpenAI API Pricing Guide 2026 — GPT-5, GPT-4o, o3 | APIMaster.ai
Complete OpenAI API pricing breakdown for GPT-5, GPT-4o, o3, and o4-mini. Compare official rates vs APIMaster.ai discounts and calculate your actual costs.
OpenAI API Pricing Guide 2026
OpenAI API pricing is usage-based: you pay per million tokens processed. This guide covers current rates for all major models, cost calculation examples, and how to reduce your OpenAI API bill with APIMaster.ai.
OpenAI API Pricing Table (Official Rates)
| Model | Input (per 1M) | Output (per 1M) | Cached Input |
|---|---|---|---|
| GPT-5.5 | $5.00 | $30.00 | $0.50 |
| GPT-5.4 | $2.50 | $15.00 | $0.25 |
| GPT-4o | $2.50 | $10.00 | $1.25 |
| GPT-4o mini | $0.15 | $0.60 | $0.075 |
| o3 | $10.00 | $40.00 | $2.50 |
| o4-mini | $1.10 | $4.40 | $0.275 |
| GPT-4o Realtime | $5.00 | $20.00 | — |
Rates from OpenAI. Check OpenAI pricing page for latest.
Discounted OpenAI API Pricing via APIMaster.ai
APIMaster provides OpenAI-compatible access to supported GPT models with live pricing and fingerprint verification.
Visit the APIMaster marketplace for live prices on each model tier.
Savings vary by model and tier. Check live pricing before estimating production costs.
How OpenAI API Pricing Works
What Is a Token?
1 token ≈ 4 characters of English text:
- "Hello, world!" = 4 tokens
- A 750-word essay ≈ 1,000 tokens
- Average API call: ~500 input + 300 output tokens
Input vs Output Tokens
OpenAI charges separately for input (your messages) and output (the response). Output tokens are typically 3–4× more expensive than input tokens.
Example:
- 10,000 API calls/day
- Avg 800 input + 400 output tokens per call
- Monthly usage: 240M input + 120M output tokens
- GPT-4o cost: 240 × $2.50 + 120 × $10 = $600 + $1,200 = $1,800/month
- GPT-4o via APIMaster: significantly lower—see marketplace for current rates
Prompt Caching
OpenAI's prompt caching reduces costs by 75% for repeated context (system prompts, long documents). Cached input tokens are billed at 25% of the standard input rate.
APIMaster passes through caching pricing where supported.
Cost Optimization Strategies
1. Choose the Right Model
Don't use a frontier model where GPT-4o mini will do:
| Task | Recommended Model | Approx. Cost vs GPT-5 |
|---|---|---|
| Classification, extraction | gpt-4o-mini | much cheaper |
| Customer support, Q&A | gpt-4o | lower cost |
| Complex analysis, research | gpt-5.5 or o3 | baseline |
| Real-time math/science | o3 or o4-mini | depends |
2. Use Prompt Caching
Place static content (instructions, reference docs) at the beginning of your prompt to maximize cache hits:
# The long system prompt is cached after the first call
response = client.chat.completions.create(
model="gpt-5.4",
messages=[
{"role": "system", "content": LONG_SYSTEM_PROMPT}, # cached
{"role": "user", "content": user_message}, # not cached
],
)
3. Truncate Long Contexts
Token usage scales linearly with context length. Summarize or truncate conversation history for long sessions:
def trim_history(messages, max_tokens=4000):
# Keep system prompt + last N messages
if len(messages) > 10:
return [messages[0]] + messages[-9:]
return messages
4. Batch Requests
For non-real-time tasks, OpenAI's Batch API offers 50% off standard prices with 24-hour turnaround. APIMaster supports batch-compatible workflows.
OpenAI API Cost Calculator
Quick formula:
cost = (input_tokens / 1_000_000 × input_price)
+ (output_tokens / 1_000_000 × output_price)
Python cost estimator:
def estimate_cost(input_tokens, output_tokens, model="gpt-5.4"):
prices = {
"gpt-5.4": (2.50, 15.00),
"gpt-4o": (2.50, 10.00),
"gpt-4o-mini": (0.15, 0.60),
"o3": (10.00, 40.00),
}
inp, out = prices.get(model, (2.50, 10.00))
return (input_tokens / 1e6 * inp) + (output_tokens / 1e6 * out)
print(f"${estimate_cost(1_000_000, 500_000, 'gpt-4o'):.2f}")
Reduce Your OpenAI API Bill
APIMaster.ai offers supported GPT models with:
- Fingerprint verification
- Multiple payment methods
- Real-time pricing dashboard
Frequently Asked Questions
How much does the OpenAI API cost? GPT-5.4 costs $2.50/M input and $15/M output. GPT-4o costs $2.50/M input and $10/M output. GPT-4o mini costs $0.15/$0.60. o3 costs $10/$40. See the full table above for all models.
Which OpenAI model is cheapest? GPT-4o mini at $0.15/M input, $0.60/M output—best for high-volume, lower-complexity tasks like classification and summarization.
How can I reduce my OpenAI API bill?
Use GPT-4o mini for simple tasks, enable prompt caching for repeated system prompts, set max_tokens limits, and use batch mode for non-real-time jobs (50% discount).
How does OpenAI API pricing compare to Claude and DeepSeek? GPT-4o and Claude Sonnet are similarly priced. DeepSeek V4 Flash can be a lower-cost option for code; compare using live APIMaster marketplace prices.
Can I use OpenAI API through APIMaster at a lower price? Yes—APIMaster offers discounted pricing on select OpenAI models. Top up from $1 with epay, PayPal, credit card, or USDT.