Colosseum 355B vs Swallow 30B
Colosseum 355B (2025) and Swallow 30B (2025) are compact production models from iGenius and Tokyo Institute of Technology. Colosseum 355B ships a 131k-token context window, while Swallow 30B ships a 16k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
Colosseum 355B fits 8x more tokens; pick it for long-context work and Swallow 30B for tighter calls.
Decision scorecard
Local evidence first| Signal | Colosseum 355B | Swallow 30B |
|---|---|---|
| Best for | general production evaluation | general production evaluation |
| Decision fit | Long context | General |
| Context window | 131k | 16k |
| Cheapest output | - | - |
| Provider routes | 0 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Colosseum 355B has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags Colosseum 355B for Long context.
- Use Swallow 30B when your own prompt tests beat the comparison signals; the local data does not show a decisive standalone advantage yet.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Colosseum 355B
Unavailable
No complete token price in local provider data
Swallow 30B
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Colosseum 355B and Swallow 30B; plan for SDK, billing, or endpoint changes.
- No overlapping tracked provider route is sourced for Swallow 30B and Colosseum 355B; plan for SDK, billing, or endpoint changes.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-03-10 | 2025-02-14 |
| Context window | 131k | 16k |
| Parameters | 355B | 30B |
| Architecture | - | - |
| License | Llama 3 Community | Llama 2 Community |
| Openness | Open weights | Open weights |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | - | 2023 |
Pricing and availability
| Pricing attribute | Colosseum 355B | Swallow 30B |
|---|---|---|
| Input price | - | - |
| Output price | - | - |
| Providers | - | - |
Pricing not yet sourced for either model.
Capabilities
| Capability | Colosseum 355B | Swallow 30B |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint is close: both models cover the core production surface. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
Pricing coverage is uneven: Colosseum 355B has no token price sourced yet and Swallow 30B has no token price sourced yet. Provider availability is 0 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Colosseum 355B when long-context analysis and larger context windows are central to the workload. Choose Swallow 30B when provider fit are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Which has a larger context window, Colosseum 355B or Swallow 30B?
Colosseum 355B supports 131k tokens, while Swallow 30B supports 16k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Colosseum 355B or Swallow 30B open source?
Colosseum 355B is listed under Llama 3 Community. Swallow 30B is listed under Llama 2 Community. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
When should I pick Colosseum 355B over Swallow 30B?
Colosseum 355B fits 8x more tokens; pick it for long-context work and Swallow 30B for tighter calls. If your workload also depends on long-context analysis, start with Colosseum 355B; if it depends on provider fit, run the same evaluation with Swallow 30B.
What is the main difference between Colosseum 355B and Swallow 30B?
Colosseum 355B and Swallow 30B differ most on context, provider coverage, capabilities, or pricing depending on the data currently sourced. Use the specs table first, then validate the model behavior with your own prompts.
Continue comparing
Last reviewed: 2026-05-19. Data sourced from public model cards and provider documentation.