Rnj-1 Instruct vs Step 3.5 Flash 2603 vs Ministral 3 8B
Ministral 3 8B comes out ahead, 68 to 63 and 50 on our weighted score.
Essential AI
Rnj-1 Instruct
50/100- ECI—
- Price$0.15 / $0.15
- Context33K
StepFunStep 3.5 Flash 2603
63/100- ECI—
- Price$0.10 / $0.30
- Context256K
- Our pick
Mistral AIMinistral 3 8B
68/100- ECI—
- Price$0.15 / $0.15
- Context262K
Ministral 3 8B is our pick
Ministral 3 8B is the better all-round choice, scoring 68/100 against Step 3.5 Flash 2603 (63) and Rnj-1 Instruct (50). It leads on inputs & features. 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 priceSame priceRnj-1 Instruct $0.15 · Step 3.5 Flash 2603 $0.15 · Ministral 3 8B $0.15 per 1M tokens (3:1 blend)
- Longest contextMinistral 3 8BMinistral 3 8B 262,144 · Step 3.5 Flash 2603 256,000 · Rnj-1 Instruct 32,768 tokens
- Widest inputsMinistral 3 8BRnj-1 Instruct: Text · Step 3.5 Flash 2603: Text · Ministral 3 8B: Text, Images
- Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
| Measure | Weight | Rnj-1 Instruct | Step 3.5 Flash 2603 | Ministral 3 8B |
|---|---|---|---|---|
| Price | 50% | 85 | 85 | 85 |
| Inputs & features | 30% | 25 | 45 | 60 |
| Context window | 20% | 0 | 36 | 37 |
| Overall | 100% | 50/100 | 63/100 | 68/100 |
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 | Rnj-1 InstructEssential AI | Step 3.5 Flash 2603StepFun | Ministral 3 8BMistral AI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.15 | $0.10 (best) | $0.15 |
| Output | $0.15 (best) | $0.30 | $0.15 (best) |
| Cached input | — | $0.02 | $0.015 (best) |
| Blended (3:1) | $0.15 | $0.15 | $0.15 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 1 providers | Official StepFun (Global) API | Official Mistral API |
| Limits | |||
| Context window | 32,768 tokens | 256,000 tokens | 262,144 tokens (best) |
| Max output | 32,768 tokens | 256,000 tokens | 262,144 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 | Yeslow · high | No |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | Yes |
| Availability | |||
| Weights | OpenApache 2.0 | Open | OpenApache 2.0 |
| API model ID | — | step-3.5-flash-2603 | ministral-8b-2512 |
| API providers | 1 | 4 | 11 (best) |
| Released | Dec 4, 2025 | Apr 2, 2026 | Dec 2, 2025 |
| Knowledge cutoff | — | Jan 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Rnj-1 Instruct$1.80
- Step 3.5 Flash 2603$1.60
- Ministral 3 8B$1.80
Which should you choose?
Which is better: Rnj-1 Instruct, Step 3.5 Flash 2603 or Ministral 3 8B?
Ministral 3 8B is the better all-round choice, scoring 68/100 against Step 3.5 Flash 2603 (63) and Rnj-1 Instruct (50). It leads on inputs & features. 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, Rnj-1 Instruct, Step 3.5 Flash 2603 or Ministral 3 8B?
Rnj-1 Instruct, Step 3.5 Flash 2603 and Ministral 3 8B cost the same: $0.15 input / $0.15 output per million tokens.
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Rnj-1 Instruct has not been scored yet, Step 3.5 Flash 2603 has not been scored yet and Ministral 3 8B has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Rnj-1 Instruct, Step 3.5 Flash 2603 and Ministral 3 8B yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Ministral 3 8B has the largest context window at 262,144 tokens, against 256,000 for Step 3.5 Flash 2603 and 32,768 for Rnj-1 Instruct. Maximum output per response: Rnj-1 Instruct up to 32,768, Step 3.5 Flash 2603 up to 256,000, Ministral 3 8B up to 262,144 tokens.
Which can read images, PDFs, audio or video?
Rnj-1 Instruct accepts text; Step 3.5 Flash 2603 accepts text; Ministral 3 8B accepts text and images. Ministral 3 8B handles the widest range of inputs.
Are any of these open source?
Yes, all three publish their weights (Apache 2.0), so you can self-host them.
Which is newer?
Step 3.5 Flash 2603 is the newest, released Apr 2, 2026. Rnj-1 Instruct came out Dec 4, 2025; Ministral 3 8B came out Dec 2, 2025. Knowledge cutoff: Step 3.5 Flash 2603 Jan 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 Nov 2, 2026.
