Skip to content
ModelCap

Seed 2.1 Turbo

API only7d #21 → #22

ByteDance Seed·#22 of 276 on the current board·cheaper than #21 DeepSeek V4 Pro 0813

Seed 2.1 Turbo is a language model from ByteDance Seed. It ranks #22 of 276 on ModelCap's current board, with an Index score of 76.3, modeled from the publisher's launch results against measured models. Its score range of 65.9–86.8 spans positions #2–#46. It is listed at $0.50 per million input tokens and $2.50 per million output tokens from one provider. It reads up to 262K tokens of context and is available only through an API.

Figures as of 28 Sept 2026, 02:38 UTC · download the public dataset · methodology

ModelCap Index · Current board
76.3#22
Modeled from the publisher's launch results against measured models · range 65.9–86.8
Market Gravity
23.7Decreased by 0.1
Secondary market signal
Input
$0.50
per 1M tokens
Output
$2.50
per 1M tokens
Context
262K
tokens
Providers
1
endpoint

Providers

Uptime measured over the last 30 minutes
ProviderInputOutputContextQuantUptime
Seedfp8$0.50$2.50262Kfp8100.0%

Publisher launch results (3)

Publisher’s own claims

Scores ByteDance Seed publishes for this model, with the figures the same tables give for other models. They are the publisher describing its own model, not independent measurement. Rows marked as used placed this model’s launch estimate against peers ModelCap measures independently, with the replay-measured optimism haircut applied; the others played no part.

BenchmarkReportedSame table, other modelsUse
NL2Repo
43.7
Claude Opus 4.7 58.2 · Seed2.1 Pro 47 · GPT-5.5 45.1 · Gemini 3.1 Pro 33.4Used in launch estimate
Terminal-Bench 2.1
67.6
GPT-5.5 73.8 · Claude Opus 4.7 71.7 · Seed2.1 Pro 71 · Gemini 3.1 Pro 70.7Used in launch estimate
ERQA
71.3
Seed2.1 Pro 72 · Gemini 3.1 Pro 70.8 · GPT-5.5 64.5 · Claude Opus 4.7 52.5Used in launch estimate

ModelCap Index · Current board

Methodology
76.3
Modeled from the publisher's launch results against measured models
Current board
#22 of 276
Score range
65.9–86.8
Rank range
#2–#46
Technical details
Public rank basis
Modeled · peer benchmarks (architecture)
Evidence label
Modeled · peer benchmarks · global-corpus-prior over 224 held-out anchors (12%); launch card against 2 resolved peers on 3 rows (88%); exceeds every named peer on 1 of 3 rows; no cross-lab optimism probe available; shrunk 3 toward the measured corpus
Index support
23.0% · limited
Identity binding
Exact catalogue product · bytedance-seed/bytedance-seed/seed-2-1-turbo · aggregates disclosed benchmark configurations · endpoint configuration not claimed
Index observations used
0
Qualified Index evidence point
76.3
How this position was produced · fused launch placement

No general-family board lists this model yet. Its point estimate is the precision-weighted mean of every channel that spoke for it; each channel’s share is the weight it carried. Independent measurements replace this placement as boards list the model.

Fused estimate
76.3 ± 8.1
Independent share
0%
Shrink toward corpus
-3.0
Peer ceiling share
33%
Optimism haircut
None applied
Method
precision-weighted-v1
Channels fused into this model’s launch placement
ChannelEstimateShare
Publisher corpus prior · not independent
global-corpus-prior over 224 held-out anchors
54.7 ± 23.512%
Launch card against resolved peers · not independent
launch card against 2 resolved peers on 3 rows
79.3 ± 8.788%
  • · Launch card row erqa: claims above every resolved peer
  • · Launch card row nl-2-repo: claims below every resolved peer
  • · Launch card row terminal-bench-2-1: claims below every resolved peer
Bayesian Evidence Score · measured evidence input only

BES normalizes admitted public benchmark evidence for measured Index rows. Its legacy score and observables prior do not define the public language rank.

Observed capability
—
Evidence status
No admitted measured evidence
General preference
—
Coding
—
Agents & tools
—
Reasoning
—
Evidence breadth
0%
Evidence coverage
0%
Market and catalogue signals · secondary, never the language Index rank
Usage (OpenRouter popularity)
5.6
Liquidity (providers × uptime)
35.5
Open reach (HF downloads)
—
Surface (context / tools / modalities)
90.3
Freshness
83.8
  • · OpenRouter popularity #241
  • · 1 live provider
  • · Catalogue: context 262144, reasoning, tools, modalities Text/Image/Video
  • · First seen 2026-08-12

These adoption and deployment observations remain context only. They do not change this model's ModelCap Index score or rank.

The bounded 0–100 capability score blends each source’s competitive placement with its published achievement, then combines capability families. Evidence breadth adds a modest uncertainty adjustment; price and popularity are not part of benchmark-led rank.

Experimental capability estimate

Estimate policy
Estimator abstained

insufficient-artifact-metadata

Feature coverage
86%
Training support
232 models · 133 lineages

insufficient-artifact-metadata. This layer predicts from admitted evidence and safe metadata only. It never enters ModelCap Score or rank.

Deployment readiness

Metadata index
30.1
limited · 38% metadata coverage
Not capability
Artifact reproducibility
0.0
Access & legal clarity
30.3
Deployability
80.0
Evaluation provenance
0.0

Not yet published: a pinned repository revision, the architecture and model type, a parameter count, safetensors weight metadata, the base model it derives from, a declared licence, a link to the licence terms, admitted benchmark results, results across several capability areas, results from more than one source, a confident match to its benchmark entries, pinned evaluation dataset versions.

A metadata completeness and deployability index—not a safety certification, quality grade, or production-readiness claim.

Market activity

Venue coverage
Market Gravity
23.7
OpenRouter weekly popularity
#241 of 334

Market Gravity uses OpenRouter’s full-catalogue popularity order. Sparse Vercel top-ten observations appear only when published and do not affect the score.

Arena preference

No matched Arena rating

This model is visible because it is available in the live catalogue, but it has no trustworthy community result yet. ModelCap does not infer a quality score from price, features, or market activity.

Market Gravity breakdown

Usage55%
5.6

OpenRouter weekly popularity across the full model catalogue.

Liquidity25%
35.5

Independent providers versus the model's open or closed cohort, weighted by uptime.

Open reach15%
50.0

Hugging Face 30-day downloads for open models; neutral for closed models.

Freshness5%
83.8

Time since first public availability, on a six-month half-life.

Specification

Model ID
bytedance-seed/seed-2-1-turbo
Context window
262K tokens
Max output
236K tokens
Inputs
Text, Image, Video
Outputs
Text
Tokenizer
Other
Cached input tokens
Not offered
First seen on OpenRouter
12 Aug 2026

Capabilities

  • Supported: Reasoning
  • Supported: Tool use
  • Supported: Structured output
  • Supported: Response format
  • Not supported: Moderated

Alternatives to Seed 2.1 Turbo, by the numbers

Ranked neighbours

Models within 3 places of #22 on the ModelCap Index.

Cheaper at a similar or higher Index

Index score within 3 points of, or above, this model's, with a lower listed blended price (3:1 input:output).

Seed 2.1 Turbo: common questions

How does Seed 2.1 Turbo rank among AI models?

Seed 2.1 Turbo holds ModelCap Index position #22 of 276 ranked language models as of 28 September 2026, with an Index score of 76.3 (interval 65.9–86.8); evidence: modeled · peer benchmarks. The Index combines public benchmark boards with published uncertainty; the methodology page explains the weighting.

How much does Seed 2.1 Turbo cost per 1M tokens?

Seed 2.1 Turbo is listed at $0.50 per 1M input tokens and $2.50 per 1M output tokens as of 28 September 2026. Prices come from the OpenRouter catalogue and re-observe on every refresh. For 1,000 requests using 2,000 input and 500 output tokens each, the listed rates imply $2.25 total (2M input + 0.5M output). This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the chosen endpoint's rate and limits before budgeting.

What is the context window of Seed 2.1 Turbo?

Seed 2.1 Turbo has a published context window of 262K tokens (262,144) and a maximum output of 236K tokens. Individual providers can serve less than the published maximum; the providers table lists each endpoint's own limit.

Is Seed 2.1 Turbo open-weight?

API only. No downloadable model weights are linked in the current source data; access is through a hosted API or product.

Which API providers serve Seed 2.1 Turbo?

One provider serves Seed 2.1 Turbo through OpenRouter as of 28 September 2026: Seed. Each provider's price, context limit, quantization and measured uptime are in the providers table above.

Which benchmarks has Seed 2.1 Turbo been evaluated on?

Seed 2.1 Turbo's Index position rests on the evidence listed on this page; it has no result on the public boards ModelCap tracks as separate leaderboards as of 28 September 2026. The evidence panel names each source and its publication date.

When was Seed 2.1 Turbo released?

Seed 2.1 Turbo first appeared in the catalogue on 12 Aug 2026. It is the current version in its family. Rank and price movements since then are recorded on the site's changes feed.