by ByteDance

Seed 2.1 Turbo review, pricing and verdict

ByteDance's cost-efficient production model in the Seed 2.1 family, priced at half of Seed 2.1 Pro on Volcano Engine for high-volume coding and agent deployments.

Best for
High-volume production agent pipelines on BytePlus or Volcano Engine
Not for
AWS Bedrock or Google Vertex deployments

By , Founder and editor

  • Available
  • Proprietary

Should you use Seed 2.1 Turbo?

Seed 2.1 Turbo suits teams running high-volume coding or agent pipelines who want most of Seed 2.1 Pro's ability at a lower rate. ByteDance's own table puts it at 67.6 on Terminal Bench 2.1 against Pro's 71.0, but no outside lab has reproduced those scores, so run your own evals before committing production traffic.

Best for

  • High-volume production agent pipelines on BytePlus or Volcano Engine Half the Volcano Engine rate of Seed 2.1 Pro with the same Seed 2.1 feature set, designed for long-chain agent task execution.
  • Coding assistance at scale Seed 2.1 series focuses on full-cycle coding delivery from requirements through validation; Turbo makes this affordable at volume.
  • Long-document and video understanding Takes text, image and video input in one request; ByteDance reports 89 on VideoMME for Turbo.

Not for

  • AWS Bedrock or Google Vertex deployments Not available on those platforms at launch; use GPT-5 Mini or Gemini 2.5 Flash for equivalent cost-tier models on managed cloud.
  • Voice or audio applications No audio input or output; use Seed 2.1 Turbo only for text and image tasks.
  • Teams requiring independently verified benchmark scores before sign-off Turbo's published scores all come from ByteDance's own evaluation table.

Seed 2.1 Turbo pricing

Input, per 1M tokens
$0.50/1M
Output, per 1M tokens
$2.50/1M
Cached input, per 1M tokens
$0.10/1M
Pricing model
per-token
Free tier
No

What a real job costs

JobInputOutputTotal
Summarise a 20-page PDF$0.015$0.0025$0.017
Support reply$0.0010$0.0007$0.0017
One coding agent run$0.100$0.050$0.150

Budgets: 20-page PDF = 30k in / 1k out · Support reply = 2k in / 300 out · Coding agent run = 200k in / 20k out. Computed from the vendor's per-token prices at render time; cached-input discounts are not applied.

Cost examples

Summarize a 50K-token document (text in, ~2K out)
$0.03
Daily coding agent (500K tokens in / 100K out)
$0.50
Customer support bot (2K in / 500 out per turn, 10K turns/day)
$22.50

BytePlus ModelArk, ByteDance's international cloud, charges $0.50 per 1M input tokens and $2.50 per 1M output tokens for Seed 2.1 Turbo, $0.10 per 1M cache-hit tokens, and $0.008333 per 1M tokens per hour for cache storage (checked 1 October 2026). Its Flex tier for low-priority jobs halves the rate to $0.25 input and $1.25 output. Inside mainland China, Volcano Engine listed Turbo at launch at CNY 3 per 1M input and CNY 15 per 1M output tokens, about $0.41 and $2.07 at June 2026 exchange rates, half of Seed 2.1 Pro's CNY 6 and CNY 30. Neither listing shows a free plan; both bill per token.

What Seed 2.1 Turbo can do

ByteDance released Seed 2.1 Turbo on 23 June 2026 as the smaller of two Seed 2.1 models, alongside Seed 2.1 Pro. It reads text, images and video within a 256K-token context window, targets coding and long-chain agent work, and is sold through Volcano Engine in China and BytePlus ModelArk elsewhere.

What goes in and what comes out

Reads

  • text
  • image
  • video
  • tool-calls

Writes

  • text
  • tool-calls

Capabilities

  • Function callingSupported
  • Structured outputSupported
  • Tool useSupported
  • Video inputSupported
  • VisionSupported
  • Audio inputNot supported
  • Audio outputNot supported
  • Code executionNot supported
  • Web browsingNot supported
Reasoning modes
standard, thinking

Key features

  • Long-Chain Agent Task Execution

    Designed for multi-step workflows covering project planning, document processing, and tool use in sequence, with ByteDance positioning it as a production-grade agent model.

  • Full-Cycle Coding Delivery

    Targets coding tasks from requirement analysis through implementation and validation, not just code completion.

  • Text, Image and Video Input

    Reads text, images and video inside a 256K-token context window, with ByteDance reporting 76.9 on MMLongBench-128K for long multimodal documents.

  • Deep Thinking Mode

    An optional reasoning mode set through thinking.type and a reasoning_effort parameter on BytePlus ModelArk.

  • OpenAI-Compatible Tool Calls

    Supports OpenAI-compatible tool calls and structured JSON responses, letting pipelines built for GPT models port with minimal rework.

Known limitations

  • Every published Turbo score comes from ByteDance's own evaluation table; none has been reproduced by an outside lab.
  • Trails Seed 2.1 Pro on motion perception, 56.8 versus 79.5 on TOMATO in ByteDance's table.

Who it is for

  • Enterprise engineering teams on Volcano Engine running high-volume coding and agent API workloads
  • Greater China companies building AI products on ByteDance cloud infrastructure
  • Cost-sensitive developers who need Seed 2.1 capabilities at half the Pro price
  • ML engineers building multimodal document processing or visual agent pipelines

Supported languages

  • Chinese (Simplified)
  • Chinese (Traditional)
  • English
  • Japanese
  • Korean
  • French
  • German
  • Spanish

Seed 2.1 Turbo benchmarks

Standout result

256K tokens

context window, with text, image and video input

Source: BytePlus ModelArk model detail page, checked 2026-10-01

Where it sits

MeasureThis modelRankMedian
Blended price (3:1)$ per 1M tokens$1.00/M#43 / 103peer median $1.71/M

Ranks are against GA models on Hokai that publish the same figure; ties share a rank.

Benchmark scores

  • Terminal-Bench 2.1 vendor-reported · 01 Oct 202667.6%Multi-step tasks completed in a real command line, % solved.

A benchmark is an exam, not the job. Scores transfer unevenly between tasks, so weigh the one closest to your workload and read every figure with its source.

Strengths and limits

Strengths

  • Ships an OpenAI-compatible API format, so existing GPT-based function-calling pipelines port with minimal rework.
  • Costs half what Pro does on Volcano Engine, yet ByteDance ships one feature set across both sizes.
  • ByteDance's model card and evaluation table cover Turbo by name, so you can see where it trails Pro before you test it.
  • A long context window with text, image and video input, listed on BytePlus ModelArk.
Show 2 more
  • OpenAI-style Chat Completions and Responses endpoints let existing GPT-based pipelines move over without schema rewrites.
  • Built for long-chain agent task execution and coding delivery end-to-end, covering requirement analysis through validation.

Limits

  • Not available on AWS Bedrock, Google Vertex AI, or Azure at launch, so teams outside BytePlus and Volcano Engine need a third-party aggregator or direct onboarding.
  • No independently verified benchmark scores for Turbo itself; all competitive-parity claims are vendor-reported only.
  • Two platforms with two names and two currencies make it easy to quote the wrong price.

Seed 2.1 Turbo alternatives

ModelLabContextIn / out per 1MReads and writes
Seed 2.1 Turbo This pageByteDance256K$0.50 / $2.50text, image, video → text
Gemini 3.1 Flash-LitePick Gemini 3.1 Flash-Lite for its published GPQA Diamond result and Google Cloud distribution; pick Seed 2.1 Turbo for video input and coding and agent work on ByteDance clouds.Google1M$0.25 / $1.50text, image, audio, video, pdf → text
GPT-4o miniPick GPT-4o mini when raw sticker price is the deciding factor; pick Seed 2.1 Turbo for ByteDance's newer Seed 2.1 architecture instead of a 2024-era OpenAI model.OpenAI128K$0.15 / $0.60text, image → text
GPT-5.6 LunaPick GPT-5.6 Luna when OpenAI's tooling and multi-cloud distribution matter more; pick Seed 2.1 Turbo if your stack already runs on BytePlus, Volcano Engine or Coze.OpenAI200K$1 / $6text, image → text, code

Seed 2.1 Turbo specs

Context window
256K tokens
Rate limit (RPM)
500
Rate limit (TPM)
1,000,000
Architecture
Transformer
Mixture of experts
No

API endpoints

NameEndpointAuth
BytePlus ModelArk (international)https://ai.byteplus.com/arkAPI Key
Volcano Engine (Volcano Ark)https://www.volcengine.com/product/arkAPI Key
Coze Ecosystemhttps://www.coze.comCoze Account

SDKs

  • Python
  • JavaScript

Prompting patterns

Show 2 prompting patterns

  • OpenAI-compatible tool schema for function calling

    { tools: [{ type: 'function', function: { name: 'search', parameters: {...} } }] }

    Seed 2.1 Turbo uses OpenAI-compatible endpoints; existing function-calling schemas port directly.

  • Explicit task decomposition in system prompt

    System: 'Break the user's request into numbered subtasks, complete each in order, and confirm completion of each before proceeding.'

    Long-chain agent tasks perform better when the model is explicitly instructed to sequence subtasks rather than attempt them all at once.

Known quirks

Show 3 known quirks

  • Volcano Engine-first distribution

    Seed 2.1 Turbo is sold through ByteDance's own clouds, Volcano Engine in mainland China and BytePlus ModelArk elsewhere, with no listing on AWS Bedrock, Google Vertex or Azure.

    Workaround: Sign up for BytePlus ModelArk outside China and point an OpenAI-style client at its Chat Completions endpoint, or reach it through Coze for no-code agents.

  • Two names and two price lists

    The same model appears as Doubao-Seed-2.1-Turbo on Volcano Engine, priced in CNY, and as Dola-Seed-2.1-turbo (ID dola-seed-2-1-turbo-260628) on BytePlus, priced in USD.

    Workaround: Search both names in docs and SDK examples, and budget from the price list of the platform you will actually call.

  • Vendor-only benchmark table

    ByteDance's Seed 2.1 page reports Turbo scores such as 67.6 on Terminal Bench 2.1, but no third party had reproduced them by 1 October 2026.

    Workaround: Run a representative internal eval on your target task type (coding, reasoning, agent) before committing Turbo to production.

Seed 2.1 Turbo facts

Deployment
API
Licence
Proprietary (ByteDance commercial API terms)
Safety posture
Balanced
Released
23 Jun 2026
Current version
doubao-seed-2.1-turbo
Family
Seed 2.1
Variant
Multimodal
Data retention
ByteDance Volcano Engine standard data retention policies apply. Enterprise teams should review the current Volcano Engine data processing agreement for retention periods, opt-out mechanisms, and data residency options.

Content restrictions

  • Applies ByteDance standard content moderation policies.
  • Refuses requests involving clear harms; configurable behavior via system prompt for enterprise use cases.

Safety controls

Rlhf
Yes
System prompt
Yes
Constitutional AI
No
Content filter API
No
Moderation endpoint
No

Data governance

HIPAA eligible
No

Version history

  • doubao-seed-2.1-turbo · 23 Jun 2026

    Seed 2.1 Turbo released 23 June 2026 with Seed 2.1 Pro; served build dola-seed-2-1-turbo-260628. Adds video input.

  • doubao-seed-2.0-pro · 14 Feb 2026

    Previous generation. Reported 76.5 SWE-bench and 98.3 AIME 2025. Succeeded by Seed 2.1 Pro and Turbo in June 2026.

What changed

  • New feature Seed 2.1 series achieves GPT-5.5 parity on coding and agent tasks (doubao-seed-2.1-turbo) source
  • Release Seed 2.1 Turbo launched on Volcano Engine (doubao-seed-2.1-turbo) source

All changes across Hokai this week

Questions about Seed 2.1 Turbo

How much do you pay for Seed 2.1 Turbo?

On BytePlus ModelArk, Seed 2.1 Turbo costs $0.50 for every 1M input tokens and $2.50 for every 1M output tokens, with cache hits at $0.10 and a Flex tier for low-priority jobs at half those rates (checked 1 October 2026). Volcano Engine in mainland China listed it at CNY 3 and CNY 15 at launch, half of what Seed 2.1 Pro charges there.

Does Seed 2.1 Turbo have a free plan?

No free plan is published. Seed 2.1 Turbo is billed per token from the first API call on both BytePlus ModelArk and Volcano Engine, so a test run of your own workload is the cheapest way to judge it.

What should you use instead of Seed 2.1 Turbo?

Gemini 3.1 Flash-Lite is the pick if you want a published 86.9% GPQA Diamond score and Google Cloud distribution. GPT-4o mini undercuts Turbo on sticker price at $0.15/$0.60 per 1M tokens but runs OpenAI's older 2024-era architecture. GPT-5.6 Luna suits teams that want OpenAI's tooling and do not want to onboard BytePlus or Volcano Engine.

Is Seed 2.1 Turbo better than Gemini 3.1 Flash-Lite?

It depends on whose numbers you need. Gemini 3.1 Flash-Lite reports 86.9% on GPQA Diamond, a test ByteDance never ran on Turbo. Turbo's case rests on its coding-and-agent focus, video input and ByteDance's own table, which no outside lab has checked yet. Anyone who needs comparable published benchmarks before sign-off is better served by Gemini 3.1 Flash-Lite today.

How do you get started with Seed 2.1 Turbo?

Outside China, open a BytePlus ModelArk account, create an API key and call the model ID dola-seed-2-1-turbo-260628 through its Chat Completions or Responses endpoint; in mainland China the same model runs on Volcano Engine. Teams that prefer a visual builder can use Coze instead. Read ByteDance's Seed 2.1 model card first for the evaluation details.

About Seed 2.1 Turbo

Seed 2.1 Turbo (internally designated Doubao-Seed-2.1-Turbo, and listed on BytePlus as Dola-Seed-2.1-turbo) is ByteDance's cost-optimized production model in the Seed 2.1 family, released in June 2026 alongside the flagship Seed 2.1 Pro. ByteDance's launch post that day presented the family as two sizes, Pro and Turbo, built around three goals: end-to-end coding delivery from requirements through validation, long-chain agent task execution, and multimodal understanding of visual and video content. It replaces Seed 2.0 Pro from February 2026, and the build served today carries the ID dola-seed-2-1-turbo-260628.

Read the full background

The official model card is a PDF that covers both sizes, linked from ByteDance's Seed 2.1 model page, and the same page prints a Turbo column in its evaluation table. On those vendor-run tests Turbo scores 67.6 on Terminal Bench 2.1 against 71.0 for Pro, 88.0 on BeyondAIME against Pro's 87.0, and 76.9 on MMLongBench-128K against 78.3. Claude Opus 4.7 and GPT-5.5 fill the rival columns, with Gemini 3.1 Pro as a third; the video rows swap in Gemini 3.5 Flash. Turbo's biggest gap to Pro is motion perception: 56.8 on TOMATO versus 79.5. No outside lab had reproduced any of these numbers by 1 October 2026, and ByteDance published no Turbo result on SWE-bench Verified, GPQA Diamond or MMLU-Pro.

BytePlus ModelArk lists Turbo with text, image and video input, text output, and a deep-thinking mode tuned with a reasoning_effort parameter. It handles function calling, structured output, MCP tools, batch jobs and prompt caching through Chat Completions and Responses endpoints. It does not produce audio or video; video generation sits in ByteDance's separate Seedance 2.5 line, and our guide to where Seedance can be used for free covers that side.

Turbo is API-only. Mainland China teams reach it through Volcano Engine (Volcano Ark) and the Doubao apps; everyone else uses BytePlus ModelArk, ByteDance's international cloud, with Coze as a no-code agent builder on top. As a Chinese company, ByteDance operates under PRC data regulations, worth reviewing directly for teams in regulated industries before production deployment.

Where the alternatives win, among the large language models Hokai tracks: if you need scores an outside lab has checked, or you buy models through AWS Bedrock, Google Vertex AI or Azure, Turbo is the wrong default. Gemini 3.1 Flash-Lite publishes its GPQA Diamond result and sits inside Google Cloud, GPT-4o mini costs less per token for light chat work, and GPT-5.6 Luna brings OpenAI's tooling and distribution. Turbo makes sense when the coding and agent workload is large, the long context window matters, and your stack can live on BytePlus or Volcano Engine.

Sources and guides

Official sources

Specifications on this page (context window, token prices, benchmark scores, licence) are read from ByteDance's own model card and documentation. The verdict is Hokai's reading of them, not the provider's claim.

Lists that include Seed 2.1 Turbo

The provider

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