GPT-5.5 Pro vs Laguna XS.2
GPT-5.5 Pro comes out ahead, 72 to 36 on our weighted score, and it is the cheaper option too.
- Our pick
OpenAIGPT-5.5 Pro
72/100- ECI162.4
- Price$30.00 / $180.00
- Context1.05M
PoolsideLaguna XS.2
36/100- ECI—
- Price—
- Context262K
Add a model
Make it a three-way comparison.
GPT-5.5 Pro is our pick
GPT-5.5 Pro is the better all-round choice, scoring 72/100 against Laguna XS.2 (36). It leads on inputs & features and context window. The score weighs inputs & features 60%, context window 40%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceGPT-5.5 ProGPT-5.5 Pro $67.50 per 1M tokens (3:1 blend) · Laguna XS.2 unpriced
- Longest contextGPT-5.5 ProGPT-5.5 Pro 1,050,000 · Laguna XS.2 262,144 tokens
- Widest inputsGPT-5.5 ProGPT-5.5 Pro: Text, Images, PDFs · Laguna XS.2: Text
- Self-hostingLaguna XS.2Publishes downloadable weights
| Measure | Weight | GPT-5.5 Pro | Laguna XS.2 |
|---|---|---|---|
| Inputs & features | 60% | 80 | 35 |
| Context window | 40% | 61 | 37 |
| Overall | 100% | 72/100 | 36/100 |
Left out because at least one model lacks the data: capability and price. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.5 ProOpenAI | Laguna XS.2Poolside |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 162.4 | — |
| ECI rank | #6 of 148 | — |
| GPQA DiamondGraduate-level science questions | 93.9% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 87.7% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% | — |
| Price per million tokens | ||
| Input | $30.00 | — |
| Output | $180.00 | — |
| Cached input | — | — |
| Blended (3:1) | $67.50 | — |
| Long-context rate | Over 272K: $60.00 / $270.00 | — |
| Price source | Official OpenAI API | — |
| Limits | ||
| Context window | 1,050,000 tokens (best) | 262,144 tokens |
| Max output | 128,000 tokens (best) | 32,768 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | Yes | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yesmedium · high · xhigh | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Open |
| API model ID | gpt-5.5-pro | — |
| API providers | 19 (best) | 1 |
| Released | Apr 23, 2026 | Apr 28, 2026 |
| Knowledge cutoff | Dec 1, 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.5 Pro$660.00
- Laguna XS.2—
Which should you choose?
Which is better: GPT-5.5 Pro or Laguna XS.2?
GPT-5.5 Pro is the better all-round choice, scoring 72/100 against Laguna XS.2 (36). It leads on inputs & features and context window. The score weighs inputs & features 60%, context window 40%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, GPT-5.5 Pro or Laguna XS.2?
GPT-5.5 Pro is cheaper at $30.00 input / $180.00 output per million tokens (official OpenAI API price). . At a typical mix of three input tokens to one output token, that is $67.50 per million tokens for GPT-5.5 Pro versus . Laguna XS.2 has no published per-token price.
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. GPT-5.5 Pro has an ECI of 162.4 and Laguna XS.2 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.5 Pro and Laguna XS.2 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
GPT-5.5 Pro has the largest context window at 1,050,000 tokens, against 262,144 for Laguna XS.2. Maximum output per response: GPT-5.5 Pro up to 128,000, Laguna XS.2 up to 32,768 tokens.
Which can read images, PDFs, audio or video?
GPT-5.5 Pro accepts text, images and PDFs; Laguna XS.2 accepts text. GPT-5.5 Pro handles the widest range of inputs.
Are any of these open source?
Laguna XS.2 publishes its weights and can be self-hosted; GPT-5.5 Pro is proprietary.
Which is newer?
Laguna XS.2 is the newest, released Apr 28, 2026. GPT-5.5 Pro came out Apr 23, 2026. Knowledge cutoff: GPT-5.5 Pro Dec 1, 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
