API cost decision in 10 seconds

NewGPT-6.1 Terra Pro vs Step 5 Preview

Pick Step 5 Preview for lower cost; pick GPT-6.1 Terra Pro only if the larger context window matters more.

Page updated: 2026-10-27T02:08:10Z Data confirmed: 2026-10-28T05:08:04Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Step 5 Preview for lower cost; pick GPT-6.1 Terra Pro only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Step 5 Preview is estimated at $2.35 vs $3.5 for GPT-6.1 Terra Pro, saving $1.15 (32.9% lower).

Cost-first pickStep 5 Preview

Context-first pickGPT-6.1 Terra Pro

Sample savings$1.1532.9%

10x traffic gap$11.5

GPT-6.1 Terra Pro has more context, but Step 5 Preview saves $1.15 on the standard workload. At 10x that traffic, the same price gap is about $11.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Step 5 Preview stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	GPT-6.1 Terra Pro	Step 5 Preview
Input-heavy / RAG	5M input + 500K output	Step 5 Preview	$7.5	$6.35
Balanced workload	1M input + 1M output	Step 5 Preview	$6	$3.7
Output-heavy chatbot	1M input + 5M output	Step 5 Preview	$26	$14.5

Cheaper input Tie $1 vs $1 / 1M

Both models report the same input price at $1 per 1M tokens.

Cheaper output Step 5 Preview $5 vs $2.7 / 1M

Step 5 Preview is $2.3 cheaper per 1M output tokens (46% lower; 1.85x difference).

Larger context GPT-6.1 Terra Pro 1.05M vs 1.05M

GPT-6.1 Terra Pro has 1.42K more context (1x larger).

Sample workload Step 5 Preview $3.5 vs $2.35

Step 5 Preview is $1.15 cheaper on the standard workload (32.9% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

GPT-6.1 Terra Pro Calculating… Estimated API cost

Step 5 Preview Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

both models tie on input price; Step 5 Preview has the lower output price; GPT-6.1 Terra Pro offers the larger context window. For the 1M input plus 500K output sample, Step 5 Preview is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $3.5 for GPT-6.1 Terra Pro and $2.35 for Step 5 Preview.

Best Fit

Choose GPT-6.1 Terra Pro when you care most about larger context window.

Choose Step 5 Preview when you care most about lower output-token price.

Decision Notes

On the standard 1M input plus 500K output workload, Step 5 Preview is estimated at $2.35 vs $3.5 for GPT-6.1 Terra Pro, saving $1.15 (32.9% lower).
Step 5 Preview is $1.15 cheaper on the standard workload (32.9% lower).
Both models report the same input price at $1 per 1M tokens.
Step 5 Preview is $2.3 cheaper per 1M output tokens (46% lower; 1.85x difference).
GPT-6.1 Terra Pro has 1.42K more context (1x larger).

Head-to-Head Specs

Feature	NewGPT-6.1 Terra Pro (OpenAI)	Step 5 Preview (StepFun)
Input Price prompt tokens per 1M	$1	$1
Completion Price per 1M tokens	$5	$2.7
Sample Workload Cost 1M input + 500K output	$3.5	$2.35
Context Window	1.05M	1.05M
Release Date	2026-10-26	2026-10-08

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Step 5 Preview	On the standard 1M input plus 500K output workload, Step 5 Preview is estimated at $2.35 vs $3.5 for GPT-6.1 Terra Pro, saving $1.15 (32.9% lower).
High-volume input processing	Tie	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Step 5 Preview	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	GPT-6.1 Terra Pro	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

gpt-oss-120b (free) can replace GPT-6.1 Terra Pro when lower sample workload cost matters most: $0.
gpt-oss-20b (free) can replace GPT-6.1 Terra Pro when lower sample workload cost matters most: $0.
gpt-oss-20b can replace GPT-6.1 Terra Pro when lower sample workload cost matters most: $0.06.
gpt-oss-20b (batch) can replace GPT-6.1 Terra Pro when lower sample workload cost matters most: $0.08.

Larger context near this budget

Grok 4.20 Multi-Agent offers 2M context with $2.5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
Llama 4 Scout offers 1.31M context with $0.25 sample workload cost.

Popular competitors

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Cheaper alternatives

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Provider catalogs

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OpenAI catalog

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StepFun catalog

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