Step 3.5 Flash vs GLM-4.7-FlashX vs Devstral Small 2
Devstral Small 2 comes out ahead, 67 to 62 and 61 on our weighted score.
StepFunStep 3.5 Flash
62/100- ECI—
- Price$0.10 / $0.30
- Context256K
Z.ai (Zhipu)GLM-4.7-FlashX
61/100- ECI—
- Price$0.07 / $0.40
- Context200K
- Our pick
Mistral AIDevstral Small 2
67/100- ECI—
- Price$0.10 / $0.30
- Context262K
Devstral Small 2 is our pick
Devstral Small 2 is the better all-round choice, scoring 67/100 against Step 3.5 Flash (62) and GLM-4.7-FlashX (61). 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 priceStep 3.5 Flash and Devstral Small 2Step 3.5 Flash $0.15 · Devstral Small 2 $0.15 · GLM-4.7-FlashX $0.152 per 1M tokens (3:1 blend)
- Longest contextDevstral Small 2Devstral Small 2 262,144 · Step 3.5 Flash 256,000 · GLM-4.7-FlashX 200,000 tokens
- Widest inputsDevstral Small 2Step 3.5 Flash: Text · GLM-4.7-FlashX: Text · Devstral Small 2: Text, Images
- Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
| Measure | Weight | Step 3.5 Flash | GLM-4.7-FlashX | Devstral Small 2 |
|---|---|---|---|---|
| Price | 50% | 89 | 89 | 89 |
| Inputs & features | 30% | 35 | 35 | 50 |
| Context window | 20% | 36 | 32 | 37 |
| Overall | 100% | 62/100 | 61/100 | 67/100 |
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 | Step 3.5 FlashStepFun | GLM-4.7-FlashXZ.ai (Zhipu) | Devstral Small 2Mistral AI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.10 | $0.07 (best) | $0.10 |
| Output | $0.30 (best) | $0.40 | $0.30 (best) |
| Cached input | $0.02 | $0.01 (best) | — |
| Blended (3:1) | $0.15 (best) | $0.152 | $0.15 (best) |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official StepFun (Global) API | Official Z.AI API | Median of 1 providers |
| Limits | |||
| Context window | 256,000 tokens | 200,000 tokens | 262,144 tokens (best) |
| Max output | 256,000 tokens | 131,072 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 | Yeslow · high | Yes | No |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | No | No |
| Availability | |||
| Weights | Open | Open | OpenApache-2.0 |
| API model ID | step-3.5-flash | glm-4.7-flashx | — |
| API providers | 8 (best) | 8 (best) | 1 |
| Released | Jan 29, 2026 | Jan 19, 2026 | Dec 9, 2025 |
| Knowledge cutoff | Jan 2025 | Apr 2025 | Dec 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Step 3.5 Flash$1.60
- GLM-4.7-FlashX$1.50
- Devstral Small 2$1.60
Which should you choose?
Which is better: Step 3.5 Flash, GLM-4.7-FlashX or Devstral Small 2?
Devstral Small 2 is the better all-round choice, scoring 67/100 against Step 3.5 Flash (62) and GLM-4.7-FlashX (61). 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, Step 3.5 Flash, GLM-4.7-FlashX or Devstral Small 2?
Step 3.5 Flash is cheaper at $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). Devstral Small 2 costs $0.10 input / $0.30 output per million tokens (median across 1 API provider); GLM-4.7-FlashX costs $0.07 input / $0.40 output per million tokens (official Z.AI API price). At a typical mix of three input tokens to one output token, that is $0.15 per million tokens for Step 3.5 Flash versus $0.15 for Devstral Small 2 (1× as much) and $0.152 for GLM-4.7-FlashX (1× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Step 3.5 Flash has not been scored yet, GLM-4.7-FlashX has not been scored yet and Devstral Small 2 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Step 3.5 Flash, GLM-4.7-FlashX and Devstral Small 2 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?
Devstral Small 2 has the largest context window at 262,144 tokens, against 256,000 for Step 3.5 Flash and 200,000 for GLM-4.7-FlashX. Maximum output per response: Step 3.5 Flash up to 256,000, GLM-4.7-FlashX up to 131,072, Devstral Small 2 up to 262,144 tokens.
Which can read images, PDFs, audio or video?
Step 3.5 Flash accepts text; GLM-4.7-FlashX accepts text; Devstral Small 2 accepts text and images. Devstral Small 2 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 is the newest, released Jan 29, 2026. GLM-4.7-FlashX came out Jan 19, 2026; Devstral Small 2 came out Dec 9, 2025. Knowledge cutoff: Step 3.5 Flash Jan 2025, GLM-4.7-FlashX Apr 2025, Devstral Small 2 Dec 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.
