Jamba Large vs Step 1 (32K) vs GPT-5 Chat
GPT-5 Chat comes out ahead, 34 to 30 and 18 on our weighted score, and it is the cheaper option too.
AI21 LabsJamba Large
30/100- ECI—
- Price$2.00 / $8.00
- Context256K
StepFunStep 1 (32K)
18/100- ECI—
- Price$2.05 / $9.59
- Context33K
- Our pick
OpenAIGPT-5 Chat
34/100- ECI—
- Price$1.25 / $10.00
- Context400K
GPT-5 Chat is our pick
GPT-5 Chat is the better all-round choice, scoring 34/100 against Jamba Large (30) and Step 1 (32K) (18). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. 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 ChatGPT-5 Chat $3.44 · Jamba Large $3.50 · Step 1 (32K) $3.94 per 1M tokens (3:1 blend)
- Longest contextGPT-5 ChatGPT-5 Chat 400,000 · Jamba Large 256,000 · Step 1 (32K) 32,768 tokens
- Widest inputsGPT-5 ChatJamba Large: Text · Step 1 (32K): Text · GPT-5 Chat: Text, Images
- Self-hostingJamba LargePublishes downloadable weights
| Measure | Weight | Jamba Large | Step 1 (32K) | GPT-5 Chat |
|---|---|---|---|---|
| Price | 50% | 24 | 22 | 24 |
| Inputs & features | 30% | 35 | 25 | 45 |
| Context window | 20% | 36 | 0 | 44 |
| Overall | 100% | 30/100 | 18/100 | 34/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Jamba LargeAI21 Labs | Step 1 (32K)StepFun | GPT-5 ChatOpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $2.00 | $2.05 | $1.25 (best) |
| Output | $8.00 (best) | $9.59 | $10.00 |
| Cached input | — | $0.41 | — |
| Blended (3:1) | $3.50 | $3.94 | $3.44 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official AI21 Labs API | Official StepFun (Global) API | Median of 2 providers |
| Limits | |||
| Context window | 256,000 tokens | 32,768 tokens | 400,000 tokens (best) |
| Max output | 4,096 tokens | 32,768 tokens | 128,000 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | No | No | Yes |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | No | No | Yes |
| Tool calling | Yes | Yes | No |
| Structured output | Yes | No | Yes |
| Availability | |||
| Weights | Open | Proprietary | Proprietary |
| API model ID | jamba-large | step-1-32k | — |
| API providers | 1 | 1 | 2 (best) |
| Released | Jul 1, 2025 | Jan 1, 2025 | Aug 7, 2025 |
| Knowledge cutoff | Aug 22, 2024 | Jun 2024 | Sep 30, 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Jamba Large$36.00
- Step 1 (32K)$39.68
- GPT-5 Chat$32.50
Which should you choose?
Which is better: Jamba Large, Step 1 (32K) or GPT-5 Chat?
GPT-5 Chat is the better all-round choice, scoring 34/100 against Jamba Large (30) and Step 1 (32K) (18). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Jamba Large, Step 1 (32K) or GPT-5 Chat?
GPT-5 Chat is cheaper at $1.25 input / $10.00 output per million tokens (median across 2 API providers). Jamba Large costs $2.00 input / $8.00 output per million tokens (official AI21 Labs API price); Step 1 (32K) costs $2.05 input / $9.59 output per million tokens (official StepFun (Global) API price). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for GPT-5 Chat versus $3.50 for Jamba Large (1× as much) and $3.94 for Step 1 (32K) (1.1× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Jamba Large has not been scored yet, Step 1 (32K) has not been scored yet and GPT-5 Chat has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Jamba Large, Step 1 (32K) and GPT-5 Chat yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Note that GPT-5 Chat does not support tool calling, which most coding agents need.
Which has the bigger context window?
GPT-5 Chat has the largest context window at 400,000 tokens, against 256,000 for Jamba Large and 32,768 for Step 1 (32K). Maximum output per response: Jamba Large up to 4,096, Step 1 (32K) up to 32,768, GPT-5 Chat up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Jamba Large accepts text; Step 1 (32K) accepts text; GPT-5 Chat accepts text and images. GPT-5 Chat handles the widest range of inputs.
Are any of these open source?
Jamba Large publishes its weights and can be self-hosted; Step 1 (32K) and GPT-5 Chat is proprietary.
Which is newer?
GPT-5 Chat is the newest, released Aug 7, 2025. Jamba Large came out Jul 1, 2025; Step 1 (32K) came out Jan 1, 2025. Knowledge cutoff: Jamba Large Aug 22, 2024, Step 1 (32K) Jun 2024, GPT-5 Chat Sep 30, 2024.
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.
