GLM-4.5-Air vs Seed 1.6 Flash vs Seed 1.6 Vision
Seed 1.6 Flash comes out ahead, 78 to 63 and 49 on our weighted score, and it is the cheaper option too.
Z.ai (Zhipu)GLM-4.5-Air
49/100- ECI—
- Price$0.20 / $1.10
- Context131K
- Our pick
ByteDance SeedSeed 1.6 Flash
78/100- ECI—
- Price$0.022 / $0.223
- Context256K
- ByteDance Seed
Seed 1.6 Vision
63/100- ECI—
- Price$0.119 / $1.19
- Context256K
Seed 1.6 Flash is our pick
Seed 1.6 Flash is the better all-round choice, scoring 78/100 against Seed 1.6 Vision (63) and GLM-4.5-Air (49). It leads on price. 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 priceSeed 1.6 FlashSeed 1.6 Flash $0.072 · Seed 1.6 Vision $0.386 · GLM-4.5-Air $0.425 per 1M tokens (3:1 blend)
- Longest contextSeed 1.6 Flash and Seed 1.6 VisionSeed 1.6 Flash 256,000 · Seed 1.6 Vision 256,000 · GLM-4.5-Air 131,072 tokens
- Widest inputsSeed 1.6 Flash and Seed 1.6 VisionGLM-4.5-Air: Text · Seed 1.6 Flash: Text, Images · Seed 1.6 Vision: Text, Images
- Self-hostingGLM-4.5-AirPublishes downloadable weights
| Measure | Weight | GLM-4.5-Air | Seed 1.6 Flash | Seed 1.6 Vision |
|---|---|---|---|---|
| Price | 50% | 68 | 100 | 69 |
| Inputs & features | 30% | 35 | 70 | 70 |
| Context window | 20% | 24 | 36 | 36 |
| Overall | 100% | 49/100 | 78/100 | 63/100 |
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 | GLM-4.5-AirZ.ai (Zhipu) | Seed 1.6 FlashByteDance Seed | Seed 1.6 VisionByteDance Seed |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.20 | $0.022 (best) | $0.119 |
| Output | $1.10 | $0.223 (best) | $1.19 |
| Cached input | $0.03 | $0.0044 (best) | $0.024 |
| Blended (3:1) | $0.425 | $0.072 (best) | $0.386 |
| Long-context rate | Same rate | Over 32K: $0.045 / $0.445 | Over 32K: $0.178 / $2.37 |
| Price source | Official Z.AI API | Official Volcengine Ark API | Official Volcengine Ark API |
| Limits | |||
| Context window | 131,072 tokens | 256,000 tokens (best) | 256,000 tokens (best) |
| Max output | 98,304 tokens (best) | 32,000 tokens | 32,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | No | Yes | Yes |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yes | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | Yes |
| Availability | |||
| Weights | Open | Proprietary | Proprietary |
| API model ID | glm-4.5-air | doubao-seed-1-6-flash-250828 | doubao-seed-1-6-vision-250815 |
| API providers | 13 (best) | 2 | 2 |
| Released | Jul 28, 2025 | Aug 28, 2025 | Aug 15, 2025 |
| Knowledge cutoff | Apr 2025 | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GLM-4.5-Air$4.20
- Seed 1.6 Flash$0.668
- Seed 1.6 Vision$3.56
Which should you choose?
Which is better: GLM-4.5-Air, Seed 1.6 Flash or Seed 1.6 Vision?
Seed 1.6 Flash is the better all-round choice, scoring 78/100 against Seed 1.6 Vision (63) and GLM-4.5-Air (49). It leads on price. 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, GLM-4.5-Air, Seed 1.6 Flash or Seed 1.6 Vision?
Seed 1.6 Flash is cheaper at $0.022 input / $0.223 output per million tokens (official Volcengine Ark API price). Seed 1.6 Vision costs $0.119 input / $1.19 output per million tokens (official Volcengine Ark API price); GLM-4.5-Air costs $0.20 input / $1.10 output per million tokens (official Z.AI API price). At a typical mix of three input tokens to one output token, that is $0.072 per million tokens for Seed 1.6 Flash versus $0.386 for Seed 1.6 Vision (5.3× as much) and $0.425 for GLM-4.5-Air (5.9× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. GLM-4.5-Air has not been scored yet, Seed 1.6 Flash has not been scored yet and Seed 1.6 Vision has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GLM-4.5-Air, Seed 1.6 Flash and Seed 1.6 Vision 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?
Seed 1.6 Flash and Seed 1.6 Vision have the largest context windows (256,000 and 256,000 tokens), against 131,072 for GLM-4.5-Air. Maximum output per response: GLM-4.5-Air up to 98,304, Seed 1.6 Flash up to 32,000, Seed 1.6 Vision up to 32,000 tokens.
Which can read images, PDFs, audio or video?
GLM-4.5-Air accepts text; Seed 1.6 Flash accepts text and images; Seed 1.6 Vision accepts text and images. Seed 1.6 Flash handles the widest range of inputs.
Are any of these open source?
GLM-4.5-Air publishes its weights and can be self-hosted; Seed 1.6 Flash and Seed 1.6 Vision is proprietary.
Which is newer?
Seed 1.6 Flash is the newest, released Aug 28, 2025. Seed 1.6 Vision came out Aug 15, 2025; GLM-4.5-Air came out Jul 28, 2025. Knowledge cutoff: GLM-4.5-Air Apr 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.
