GPT-5.5 vs Doubao Seed 2.1 Turbo
GPT-5.5 wins on Overall, Coding, Multimodal. Every numeric field is compared below, with a worked monthly-cost example and a pick rule for each use case.
Verdict at a glance
Choose GPT-5.5 if you…
- Balanced with no weak spot
- Richest ecosystem
- Mature plugin/function calling
- Strong creative writing
- Best for: General tasks, Creative writing, Coding
Choose Doubao Seed 2.1 Turbo if you…
- Low price
- Video support
- Fast
- Built for volume
- Best for: Volume production, Video, Low cost
Head-to-head aggregate scores
Scores are 0–100, aggregated from public benchmark information and independently weighted across three leaderboards. Rank is out of 22 tracked models.
Aggregated from public sources and independently weighted; methodology on the Terms page. Scores within 3 points are treated as statistically tied.
Specs & pricing — every field side by side
List API prices in USD per 1M tokens. The highlighted cell is the stronger value/capability on that row.
| Dimension | GPT-5.5 | Doubao Seed 2.1 Turbo | Verdict |
|---|---|---|---|
| Vendor | OpenAI (US) | ByteDance (CN) | Different vendors |
| Released | 2026.04 | 2026.06 | Doubao Seed 2.1 Turbo is newer |
| Overall (rank) | 81 · #5 | 63 · #20 | GPT-5.5 +18 |
| Coding | 75 · #8 | 61 · #19 | GPT-5.5 +14 |
| Multimodal | 85 · #8 | 73 · #17 | GPT-5.5 +12 |
| Context window | 1.05M | 256K | GPT-5.5 larger |
| Max output | 128K | 256K | Doubao Seed 2.1 Turbo longer |
| Effective-context | 90 | 90 | Tie |
| Input $/1M | $5 | $0.42 | Doubao Seed 2.1 Turbo cheaper |
| Output $/1M | $30 | $2.08 | Doubao Seed 2.1 Turbo cheaper |
| Cache discount | 50% off | custom | GPT-5.5 deeper |
| Speed | ~50 tok/s | ~75 tok/s | Doubao Seed 2.1 Turbo faster |
| TTFT | 0.8s | 0.4s | Doubao Seed 2.1 Turbo snappier |
| Function calling | 95 | 80 | GPT-5.5 ahead |
| Refusal rate | ~15% | ~10% | Doubao Seed 2.1 Turbo less restrictive |
| English | 94 | 68 | GPT-5.5 |
| Chinese | 76 | 90 | Doubao Seed 2.1 Turbo |
| Modalities | text, image | text, image, video | different coverage |
| Open weights | No | No | Both closed |
| Fine-tuning | Yes | Yes | |
| Free tier | ChatGPT free tier available (rate-limited); Plus $20/month | Doubao App free | |
| SOC2 / no-train | yes / yes | no / yes | |
| Private deployment | No | Yes | Doubao Seed 2.1 Turbo |
Fields drawn from vendor public documentation and the Modelspectra 22-model dataset; speed varies with network, concurrency and prompt length. Verify current pricing before purchase.
Dimension-by-dimension analysis
Reasoning & overall intelligence
GPT-5.5 leads the overall aggregate by 18 points (81 vs 63). That is a meaningful, not marginal, edge on hard, multi-step reasoning, while Doubao Seed 2.1 Turbo remains a strong generalist that is not out of its depth on routine work.
Agentic coding
This is a clear gap: GPT-5.5 scores 75 against 61. On multi-file edits, SWE-style tickets and long-horizon agent loops GPT-5.5 needs fewer correction turns; Doubao Seed 2.1 Turbo is still competent for scripts and assisted completion but trails as task complexity rises.
Multimodal
GPT-5.5 leads multimodal 85 vs 73. A concrete modality difference: Doubao Seed 2.1 Turbo additionally handles video.
Speed & latency
Doubao Seed 2.1 Turbo is faster in interactive use: ~75 tok/s with 0.4s TTFT versus ~50 tok/s with 0.8s TTFT (about 1.5× the throughput). For conversational UIs where perceived responsiveness drives retention, that edge is a real product factor even when raw reasoning is lower.
Context: window vs usable recall
Nominal windows are 1.05M for GPT-5.5 and 256K for Doubao Seed 2.1 Turbo. Effective-context scores point the same way as window size — GPT-5.5 is ahead on usable recall (90 vs 90), so prefer it for long-document work where details cannot be missed.
Price & total cost
Doubao Seed 2.1 Turbo is the cheaper API at $0.42/$2.08 versus GPT-5.5 at $5/$30 per 1M input/output tokens — list input is about 11.9× lower. Cache discounts (GPT-5.5 50%) shift the effective bill, worked out below.
Chinese vs English
English: GPT-5.5 94 vs Doubao Seed 2.1 Turbo 68. Chinese: 76 vs 90. For Chinese-language production, Doubao Seed 2.1 Turbo is the stronger pick. Note that non-Chinese models generally require overseas network access for their APIs.
Tool use & ecosystem
Function-calling score: GPT-5.5 95 vs Doubao Seed 2.1 Turbo 80, so GPT-5.5 has the edge on structured tool use. Fine-tuning is available from GPT-5.5 and Doubao Seed 2.1 Turbo. Factor in existing SDK/plugin familiarity — switching cost often outweighs a few-point tool-use gap.
Cost worked example — same workload, real token math
Assume a production workload of 100M input + 30M output tokens per month, with 90% of input tokens served from cache. Figures use public list prices.
| Scenario · per month | GPT-5.5 | Doubao Seed 2.1 Turbo | Gap |
|---|---|---|---|
| List priceno cache applied | $1,400100M in × $5 + 30M out × $30 | $104100M in × $0.42 + 30M out × $2.08 | 13.46×gap |
| With caching90% of inputs cache-hit | $1,17590M cached in × $2.5 + 10M in × $5 + 30M out × $30 | $104no published cache discount | 11.30×gap |
Illustrative model; your input/output mix and cache-hit ratio change the result. Prices are list rates before any enterprise agreement.