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Head-to-head comparison

o3 vs Laguna S 2.1

o3 (OpenAI) and Laguna S 2.1 (Poolside) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 15 September 2026

As of 15 September 2026, Laguna S 2.1 holds the stronger ModelCap Index position (#45 vs #49); Laguna S 2.1 is 44.4× cheaper per output token ($0.18/1M vs $8.00/1M); and Laguna S 2.1 offers the longer context window (1M vs 200K tokens).

Which should you choose?

Choose o3 if…

  • ModelCap publishes no field on which o3 leads Laguna S 2.1 for this pair.

Choose Laguna S 2.1 if…

  • you want the stronger overall ModelCap Index position — #45 against #49 (62.6 vs 61.3 points).
  • API cost matters — $0.18/1M output tokens against $8.00/1M, about 44.4× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.09/1M against $2.00/1M.
  • you need the longer context window — 1M tokens against 200K.
  • you want the more recently listed model — Laguna S 2.1 was listed 21 July 2026, o3 16 April 2025.

o3 vs Laguna S 2.1: specs, pricing and context

Specification comparison of o3 and Laguna S 2.1
Fieldo3OpenAILaguna S 2.1Poolside
ModelCap Index position#49#45
Index score61.362.6
EvidenceMeasuredEstimated
Input price / 1M tokens$2.00$0.09
Output price / 1M tokens$8.00$0.18
Context window200K tokens1M tokens
Max output tokens100K131K
API providers listed11
Weight accessAPI onlyRestricted license
Input modalitiesImage, Text, FileText
First listed16 April 202521 July 2026
PublisherOpenAIPoolside

Evidence: 3 public benchmark observations across 3 boards · 5 reported rows against measured corpus ladders (67%); global-corpus-prior over 194 held-out anchors (33%); shrunk 5.2 toward the measured corpus. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: o3 vs Laguna S 2.1

Public benchmark boards where o3 or Laguna S 2.1 has a published result
Boardo3Laguna S 2.1Leads
Arena codingArena (LMArena)14601454–1467—Only one result
ARC-AGI-2ARC Prize Foundation6.5%High—Only one result
SWE-benchSWE-bench (Princeton / SWE-agent team)58.4%—Only one result
BFCL V4UC Berkeley (Gorilla)63.1Prompt—Only one result
AA τ²-Bench TelecomArtificial Analysis80.7%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="o3":reasoning=true—Only one result
AA Humanity's Last ExamArtificial Analysis20.1%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="o3":reasoning=true—Only one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

o3 vs Laguna S 2.1: common questions

Is o3 better than Laguna S 2.1?

Laguna S 2.1 ranks higher on the ModelCap Index as of 15 September 2026: #45 against #49. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is o3 cheaper than Laguna S 2.1?

Laguna S 2.1 is cheaper on output tokens: $0.18/1M against $8.00/1M. Input tokens are $2.00/1M for o3 and $0.09/1M for Laguna S 2.1. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $8.00 for o3 versus $0.27 for Laguna S 2.1. Laguna S 2.1 costs 96.6% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, o3 or Laguna S 2.1?

Laguna S 2.1 has the larger context window: 1M tokens against 200K.

Which is better for coding, o3 or Laguna S 2.1?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are o3 and Laguna S 2.1 open-weight models?

o3: API only. Laguna S 2.1: Restricted license. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run o3 and Laguna S 2.1?

ModelCap currently lists 1 API provider for o3 and 1 for Laguna S 2.1, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this o3 vs Laguna S 2.1 comparison?

Every figure comes from the sealed ModelCap dataset published 15 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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