Seed 1.6 Flash vs GPT-5.5 Pro
Seed 1.6 Flash costs 600.0x less per output token than GPT-5.5 Pro ($0.30 vs $180.00 per million). Updated October 22, 2026; no benchmark has tested both models yet.
- Coding
- No data
- Overall
- No data
- Output $/M
- $0.30
- Coding
- No data
- Overall
- No data
- Output $/M
- $180.00
Seed 1.6 Flash or GPT-5.5 Pro: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Seed 1.6 Flash for output tokens 600.0x cheaper ($0.30 vs $180.00 per million).
No benchmark has tested both yet. Seed 1.6 Flash has none yet; GPT-5.5 Pro on Epoch Capabilities Index, ARC-AGI and ARC-AGI-2. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Long documents
Listed context window
GPT-5.5 Pro
GPT-5.5 Pro takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Seed 1.6 Flash
Seed 1.6 Flash $0.0002, GPT-5.5 Pro $0.120 per turn.
List prices
At a glance
- Coding index
- Seed 1.6 Flash not benchmarked, GPT-5.5 Pro not benchmarked.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Seed 1.6 Flash $0.30 against GPT-5.5 Pro $180.00 per million output tokens, 600.0x apart.
- Context window
- Seed 1.6 Flash takes 262K tokens, GPT-5.5 Pro 1.05M.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board measured
| Benchmark | Seed 1.6 Flash | GPT-5.5 Pro | Leader |
|---|---|---|---|
| Epoch Capabilities Index | Not measured | 162.9 | Only GPT-5.5 Pro measured |
| Neither model has a result on the other 1 board here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index4 boards measured
| Benchmark | Seed 1.6 Flash | GPT-5.5 Pro | Leader |
|---|---|---|---|
| ARC-AGI | Not measured | 96.5% | Only GPT-5.5 Pro measured |
| ARC-AGI-2 | Not measured | 84.6% | Only GPT-5.5 Pro measured |
| SimpleBench | Not measured | 76.9% | Only GPT-5.5 Pro measured |
| Chess puzzles | Not measured | 62.0% | Only GPT-5.5 Pro measured |
| Neither model has a result on the other 19 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | Seed 1.6 Flash | GPT-5.5 Pro | Leader |
|---|---|---|---|
| FrontierMath, tiers 1 to 3 | Not measured | 87.7% | Only GPT-5.5 Pro measured |
| FrontierMath, tier 4 | Not measured | 78.0% | Only GPT-5.5 Pro measured |
| Neither model has a result on the other 12 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Seed 1.6 Flash costs less
Repository review
50K input + 3K output tokens
Seed 1.6 Flash costs less
Agent loop
200K input + 10K output tokens
Seed 1.6 Flash costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | ByteDance Seed Seed 1.6 Flash | OpenAI GPT-5.5 Pro |
|---|---|---|
| Maker | ByteDance Seed | OpenAI |
| Weights | No public weights listed | No public weights listed |
| Released | December 23, 2025 | April 24, 2026 |
| Context window | 262K | 1.05M |
| Input $/Mtok | $0.075 | $30.00 |
| Output $/Mtok | $0.30 | $180.00 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Seed 1.6 Flash better than GPT-5.5 Pro for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Seed 1.6 Flash for output tokens 600.0x cheaper ($0.30 vs $180.00 per million).
Which is cheaper, Seed 1.6 Flash or GPT-5.5 Pro?
Seed 1.6 Flash costs $0.075 per million input tokens and $0.30 per million output tokens; GPT-5.5 Pro costs $30.00 and $180.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Seed 1.6 Flash or GPT-5.5 Pro?
GPT-5.5 Pro, with 1.05M tokens against 262K.
Has any benchmark tested both Seed 1.6 Flash and GPT-5.5 Pro?
No benchmark has tested both yet. Seed 1.6 Flash has none yet; GPT-5.5 Pro on Epoch Capabilities Index, ARC-AGI and ARC-AGI-2. Compare them on price and context instead. Data as of October 22, 2026.