API cost decision in 10 seconds

NewKimi K3.1 Pro vs Solar Mini 4

Pick Solar Mini 4 for lower cost; pick Kimi K3.1 Pro only if the larger context window matters more.

Page updated: 2026-10-23T19:08:09Z Data confirmed: 2026-10-23T20:08:09Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Solar Mini 4 for lower cost; pick Kimi K3.1 Pro only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Solar Mini 4 is estimated at $0.15 vs $7 for Kimi K3.1 Pro, saving $6.85 (97.9% lower).

Cost-first pickSolar Mini 4

Context-first pickKimi K3.1 Pro

Sample savings$6.8597.9%

10x traffic gap$68.5

Kimi K3.1 Pro has more context, but Solar Mini 4 saves $6.85 on the standard workload. At 10x that traffic, the same price gap is about $68.5. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Solar Mini 4 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Kimi K3.1 Pro	Solar Mini 4
Input-heavy / RAG	5M input + 500K output	Solar Mini 4	$15	$0.35
Balanced workload	1M input + 1M output	Solar Mini 4	$12	$0.25
Output-heavy chatbot	1M input + 5M output	Solar Mini 4	$52	$1.05

Cheaper input Solar Mini 4 $2 vs $0.05 / 1M

Solar Mini 4 is $1.95 cheaper per 1M input tokens (97.5% lower; 40x difference).

Cheaper output Solar Mini 4 $10 vs $0.2 / 1M

Solar Mini 4 is $9.8 cheaper per 1M output tokens (98% lower; 50x difference).

Larger context Kimi K3.1 Pro 1.05M vs 524.29K

Kimi K3.1 Pro has 524.29K more context (2x larger).

Sample workload Solar Mini 4 $7 vs $0.15

Solar Mini 4 is $6.85 cheaper on the standard workload (97.9% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Kimi K3.1 Pro Calculating… Estimated API cost

Solar Mini 4 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

Solar Mini 4 has the lower input price; Solar Mini 4 has the lower output price; Kimi K3.1 Pro offers the larger context window. For the 1M input plus 500K output sample, Solar Mini 4 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $7 for Kimi K3.1 Pro and $0.15 for Solar Mini 4.

Best Fit

Choose Kimi K3.1 Pro when you care most about larger context window.

Choose Solar Mini 4 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, Solar Mini 4 is estimated at $0.15 vs $7 for Kimi K3.1 Pro, saving $6.85 (97.9% lower).
Solar Mini 4 is $6.85 cheaper on the standard workload (97.9% lower).
Solar Mini 4 is $1.95 cheaper per 1M input tokens (97.5% lower; 40x difference).
Solar Mini 4 is $9.8 cheaper per 1M output tokens (98% lower; 50x difference).
Kimi K3.1 Pro has 524.29K more context (2x larger).

Head-to-Head Specs

Feature	NewKimi K3.1 Pro (MoonshotAI)	Solar Mini 4 (Upstage)
Input Price prompt tokens per 1M	$2	$0.05
Completion Price per 1M tokens	$10	$0.2
Sample Workload Cost 1M input + 500K output	$7	$0.15
Context Window	1.05M	524.29K
Release Date	2026-10-23	2026-09-23

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Solar Mini 4	On the standard 1M input plus 500K output workload, Solar Mini 4 is estimated at $0.15 vs $7 for Kimi K3.1 Pro, saving $6.85 (97.9% lower).
High-volume input processing	Solar Mini 4	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Solar Mini 4	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Kimi K3.1 Pro	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Kimi K2.7 Code (free) can replace Kimi K3.1 Pro when lower sample workload cost matters most: $0.
Kimi K2.6 (free) can replace Kimi K3.1 Pro when lower sample workload cost matters most: $0.
Kimi K2 0711 can replace Kimi K3.1 Pro when lower sample workload cost matters most: $1.72.
Kimi K2.5 can replace Kimi K3.1 Pro when lower sample workload cost matters most: $1.75.

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.
MiMo-V2.6-Flash offers 1.05M context with $0.28 sample workload cost.

Popular competitors

DeepSeek V4.1 Flash · DeepSeek · #1
DeepSeek V4.1 Flash 1017 · DeepSeek · #2
GLM 5.3 Flash · Z.ai · #3
Hy4 preview · Tencent · #4

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

MoonshotAI catalog

Review all tracked MoonshotAI models before deciding whether this matchup is the right shortlist.

Open MoonshotAI models

Upstage catalog

Check other Upstage models with comparable pricing, context, or release timing.

Open Upstage models

Kimi K3.1 Pro

Kimi K3.1 Pro is Moonshot AI's flagship open-weight multimodal reasoning model and a post-trained successor to Kimi K3, with a 1M-token context window. It is built for long-horizon coding, 3D...

Solar Mini 4

Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524K context window. It is built for agentic use cases where response...