API cost decision in 10 seconds

🔥Step 5 Preview vs NewLFM3-1.7B

Pick LFM3-1.7B for lower cost; pick Step 5 Preview only if the larger context window matters more.

Page updated: 2026-11-07T01:07:40Z Data confirmed: 2026-11-07T02:07:38Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick LFM3-1.7B for lower cost; pick Step 5 Preview only if the larger context window matters more.

On the standard 1M input plus 500K output workload, LFM3-1.7B is estimated at $0.18 vs $2.35 for Step 5 Preview, saving $2.17 (92.3% lower).

Cost-first pickLFM3-1.7B

Context-first pickStep 5 Preview

Sample savings$2.1792.3%

10x traffic gap$21.7

Step 5 Preview has more context, but LFM3-1.7B saves $2.17 on the standard workload. At 10x that traffic, the same price gap is about $21.7. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

LFM3-1.7B stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Step 5 Preview	LFM3-1.7B
Input-heavy / RAG	5M input + 500K output	LFM3-1.7B	$6.35	$0.5
Balanced workload	1M input + 1M output	LFM3-1.7B	$3.7	$0.28
Output-heavy chatbot	1M input + 5M output	LFM3-1.7B	$14.5	$1.08

Cheaper input LFM3-1.7B $1 vs $0.08 / 1M

LFM3-1.7B is $0.92 cheaper per 1M input tokens (92% lower; 12.5x difference).

Cheaper output LFM3-1.7B $2.7 vs $0.2 / 1M

LFM3-1.7B is $2.5 cheaper per 1M output tokens (92.6% lower; 13.5x difference).

Larger context Step 5 Preview 1.05M vs 262.14K

Step 5 Preview has 786.43K more context (4x larger).

Sample workload LFM3-1.7B $2.35 vs $0.18

LFM3-1.7B is $2.17 cheaper on the standard workload (92.3% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Step 5 Preview Calculating… Estimated API cost

LFM3-1.7B 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

LFM3-1.7B has the lower input price; LFM3-1.7B has the lower output price; Step 5 Preview offers the larger context window. For the 1M input plus 500K output sample, LFM3-1.7B is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2.35 for Step 5 Preview and $0.18 for LFM3-1.7B.

Best Fit

Choose Step 5 Preview when you care most about larger context window.

Choose LFM3-1.7B when you care most about lower input-token price, and lower output-token price.

Decision Notes

On the standard 1M input plus 500K output workload, LFM3-1.7B is estimated at $0.18 vs $2.35 for Step 5 Preview, saving $2.17 (92.3% lower).
LFM3-1.7B is $2.17 cheaper on the standard workload (92.3% lower).
LFM3-1.7B is $0.92 cheaper per 1M input tokens (92% lower; 12.5x difference).
LFM3-1.7B is $2.5 cheaper per 1M output tokens (92.6% lower; 13.5x difference).
Step 5 Preview has 786.43K more context (4x larger).

Head-to-Head Specs

Feature	🔥Step 5 Preview (StepFun)	NewLFM3-1.7B (LiquidAI)
Input Price prompt tokens per 1M	$1	$0.08
Completion Price per 1M tokens	$2.7	$0.2
Sample Workload Cost 1M input + 500K output	$2.35	$0.18
Context Window	1.05M	262.14K
Release Date	2026-10-08	2026-11-06
Popularity	#7

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	LFM3-1.7B	On the standard 1M input plus 500K output workload, LFM3-1.7B is estimated at $0.18 vs $2.35 for Step 5 Preview, saving $2.17 (92.3% lower).
High-volume input processing	LFM3-1.7B	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	LFM3-1.7B	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Step 5 Preview	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Step 3.5 Flash can replace Step 5 Preview when lower sample workload cost matters most: $0.25.
Step 3.7 Flash can replace Step 5 Preview when lower sample workload cost matters most: $0.77.
LFM3-1.7B (free) can replace LFM3-1.7B when lower sample workload cost matters most: $0.
LFM2.5-2.6B (free) can replace LFM3-1.7B when lower sample workload cost matters most: $0.

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.
GPT-6 Luna offers 1.05M context with $0.35 sample workload cost.

Popular competitors

Kimi K3.1 Pro · MoonshotAI · #1
DeepSeek V4.1 Flash 1017 · DeepSeek · #2
DeepSeek V4.1 Flash · DeepSeek · #3
GLM 5.3 Flash · Z.ai · #4

Cheaper alternatives

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Larger context alternatives

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Provider catalogs

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StepFun catalog

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LiquidAI catalog

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Step 5 Preview

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...

LFM3-1.7B

A compact 1.7B-parameter text model with a 256K-token context, post-trained for agents, tool calling, and structured outputs. It reasons before it answers. Prompts and outputs may be retained and used...