Seed 1.8 vs GPT-5.1
Benchmark Performance
Available Benchmarks
Technical Differences
Side-by-Side Facts
| Field | Seed 1.8 | GPT-5.1 |
|---|---|---|
| Developer | ByteDance Seed | Openai |
| Family | Seed 1 8 | Gpt 5 1 |
| Model | Seed 1.8 | GPT-5.1 |
| Version | Seed 1.8 | GPT-5.1 |
| Lifecycle | active | active |
| Released | Unknown | 2025-11-13 |
| Knowledge cutoff | Unknown | 2024-09-30 |
| Input modalities | Text, Image | Unknown |
| Output modalities | Text | Unknown |
| Context window | Unknown | 400,000 |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Unknown | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
9 comparable fields · 5 material differences · Interactive comparison only; indexing gate not met
Seed 1.8 Capabilities
GPT-5.1 Capabilities
Internal Comparison Graph
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Primary Evidence
Sources and Freshness
Questions
Seed 1.8 vs GPT-5.1 FAQs
Is Seed 1.8 or GPT-5.1 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Seed 1.8 and GPT-5.1, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Seed 1.8 or GPT-5.1?+
Only GPT-5.1 has a directly sourced input price: $1.25 per million tokens. Only GPT-5.1 has a directly sourced output price: $10.00 per million tokens.
Which has a larger context window, Seed 1.8 or GPT-5.1?+
Neither model has a larger sourced context window in this comparison. Seed 1.8 is — and GPT-5.1 is 400,000.
Which performs better in benchmarks, Seed 1.8 or GPT-5.1?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Seed 1.8 or GPT-5.1 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Seed 1.8 is not marked open weight; GPT-5.1 is not marked open weight.
Can Seed 1.8 and GPT-5.1 understand images?+
Seed 1.8 is documented with image input; GPT-5.1 is not documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Seed 1.8 or GPT-5.1?+
Neither has a larger sourced maximum output. Seed 1.8 is — and GPT-5.1 is 128,000.
Do Seed 1.8 and GPT-5.1 support reasoning and tool use?+
Seed 1.8: reasoning, tool calling, and image input. GPT-5.1: reasoning and tool calling. Feature support does not establish relative quality.
Which is available from more inference providers, Seed 1.8 or GPT-5.1?+
Seed 1.8 has 0 sourced provider routes; GPT-5.1 has 2, so GPT-5.1 has broader tracked availability.
Which offers better value, Seed 1.8 or GPT-5.1?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.