O3 Pro
OpenAI · text, image → text
o3-pro This model only supports Requests API interface requests.The model's thinking time is relatively long, so the response will be slow.
Input$20 /M
Output$80 /M
← ModelsO3 Pro
Step 3.7 Flash
O3 Pro vs Step 3.7 Flash
Compare O3 Pro from OpenAI and Step 3.7 Flash from StepFun on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
O3 ProStep 3.7 Flash+ Add model · 2/4
Step 3.7 Flash
StepFun · text, image, video → text
step-3.7-flash is stepfun's flagship inference model, designed for high-complexity tasks that require deep reasoning and fast execution. It excels at decomposing multi-step problems, performing tool calls, and maintaining consistency across massive datasets. It is the preferred choice for complex workloads such as long-context agents, advanced software engineering, and end-to-end research automation.
Input$0.22 /M
Output$1.32 /M
Cache read$0.044 /M
Pricing & Specifications
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
O3 Pro
Step 3.7 Flash
Input /M
$20
$0.22
Output /M
$80
$1.32
Cache read /M
-
$0.044
Context length
200,000
256,000
Max output
100,000
0
Time to First Token
88.9 s
1.4 s
Throughput
12.6 tok/s
32.6 tok/s
Modalities
textimage
textimagevideo
Supported Parameters
thinkingtoolsfunction callingstructured outputs
API Formats
Released
June 10, 2025
May 29, 2026
Promotional prices show the discounted rate; see each model page for promotion windows.
Activity Past 30 Days
Daily traffic served through AIHubMix — how demand for each model is trending.
o3-prostep-3.7-flash
Tokens / day
-
Requests / day
-
Performance Past 3 Days
Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.
o3-prostep-3.7-flash
Throughput (tok/s)
-
TTFT (s)
-
Uptime (%)
-
Cost calculator
Estimate your monthly bill for the same workload on each model.
Step 3.7 Flash
$33.00 /mo
O3 Pro
$2,400 /mo
Monthly = daily × 30. Discounted rates applied where a promotion is active.
FAQ
Which is cheaper: O3 Pro, Step 3.7 Flash?
Step 3.7 Flash: $1.32/M output tokens; O3 Pro: $80/M. Use the cost calculator above to estimate your own workload.
Which responds faster?
Step 3.7 Flash: 1.4s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.
How large is each context window?
O3 Pro accepts 200,000 and Step 3.7 Flash accepts 256,000 input tokens.
Which one generates tokens faster?
Step 3.7 Flash at 32.6 tok/s and O3 Pro at 12.6 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.
What inputs and capabilities does each model support?
O3 Pro accepts text and image input and supports thinking, tool calling, function calling and structured outputs; Step 3.7 Flash accepts text, image and video input.
Can I call O3 Pro and Step 3.7 Flash with the same API key?
Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.
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