API cost decision in 10 seconds

Solar Pro 4 vs Laguna XS 2.1 (free)

Pick Laguna XS 2.1 (free) for lower cost; pick Solar Pro 4 only if the larger context window matters more.

Page updated: 2026-08-13T13:07:45Z Data confirmed: 2026-08-23T14:07:50Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Laguna XS 2.1 (free) for lower cost; pick Solar Pro 4 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Laguna XS 2.1 (free) is estimated at $0 vs $0.09 for Solar Pro 4, saving $0.09 (100% lower).

Cost-first pickLaguna XS 2.1 (free)

Context-first pickSolar Pro 4

Sample savings$0.09100%

10x traffic gap$0.9

Solar Pro 4 has more context, but Laguna XS 2.1 (free) saves $0.09 on the standard workload. At 10x that traffic, the same price gap is about $0.9. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Laguna XS 2.1 (free) stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Solar Pro 4	Laguna XS 2.1 (free)
Input-heavy / RAG	5M input + 500K output	Laguna XS 2.1 (free)	$0.21	$0
Balanced workload	1M input + 1M output	Laguna XS 2.1 (free)	$0.15	$0
Output-heavy chatbot	1M input + 5M output	Laguna XS 2.1 (free)	$0.63	$0

Cheaper input Laguna XS 2.1 (free) $0.03 vs $0 / 1M

Laguna XS 2.1 (free) is free for input tokens while Solar Pro 4 costs $0.03 per 1M tokens.

Cheaper output Laguna XS 2.1 (free) $0.12 vs $0 / 1M

Laguna XS 2.1 (free) is free for output tokens while Solar Pro 4 costs $0.12 per 1M tokens.

Larger context Solar Pro 4 524.29K vs 262.14K

Solar Pro 4 has 262.14K more context (2x larger).

Sample workload Laguna XS 2.1 (free) $0.09 vs $0

Laguna XS 2.1 (free) is free for the standard workload while the other model is estimated at $0.09.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Solar Pro 4 Calculating… Estimated API cost

Laguna XS 2.1 (free) 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

Laguna XS 2.1 (free) has the lower input price; Laguna XS 2.1 (free) has the lower output price; Solar Pro 4 offers the larger context window. For the 1M input plus 500K output sample, Laguna XS 2.1 (free) is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.09 for Solar Pro 4 and $0 for Laguna XS 2.1 (free).

Best Fit

Choose Solar Pro 4 when you care most about larger context window.

Choose Laguna XS 2.1 (free) 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, Laguna XS 2.1 (free) is estimated at $0 vs $0.09 for Solar Pro 4, saving $0.09 (100% lower).
Laguna XS 2.1 (free) is free for the standard workload while the other model is estimated at $0.09.
Laguna XS 2.1 (free) is free for input tokens while Solar Pro 4 costs $0.03 per 1M tokens.
Laguna XS 2.1 (free) is free for output tokens while Solar Pro 4 costs $0.12 per 1M tokens.
Solar Pro 4 has 262.14K more context (2x larger).

Head-to-Head Specs

Feature	Solar Pro 4 (Upstage)	Laguna XS 2.1 (free) (Poolside)
Input Price prompt tokens per 1M	$0.03	$0
Completion Price per 1M tokens	$0.12	$0
Sample Workload Cost 1M input + 500K output	$0.09	$0
Context Window	524.29K	262.14K
Release Date	2026-08-10	2026-07-02

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Laguna XS 2.1 (free)	On the standard 1M input plus 500K output workload, Laguna XS 2.1 (free) is estimated at $0 vs $0.09 for Solar Pro 4, saving $0.09 (100% lower).
High-volume input processing	Laguna XS 2.1 (free)	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Laguna XS 2.1 (free)	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Solar Pro 4	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

No lower-cost same-provider swap is currently tracked for this pair.

Larger context near this budget

DeepSeek V4 Flash Latest offers 1.31M context with $0.11 sample workload cost.
Owl Alpha offers 1.05M context with $0 sample workload cost.
Ox Alpha offers 1.05M context with $0 sample workload cost.
DeepSeek V4 Flash 0423 offers 1.05M context with $0.1 sample workload cost.

Popular competitors

DeepSeek V4 Flash 0731 · DeepSeek · #1
MiMo-V2.5 · Xiaomi · #2
Hy3 · Tencent · #3
Ox Alpha · stealth · #4

Cheaper alternatives

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Provider catalogs

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

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Upstage catalog

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

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Poolside catalog

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

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Solar Pro 4

Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in office productivity, document-intensive...

Laguna XS 2.1 (free)

Laguna XS 2.1 is the latest coding agent model in the 33B-A3B category from [Poolside](https://poolside.ai/) and a step forward from their Laguna XS.2 model (released in April 2026). It combines...