Pairwise benchmark snapshot · Aug 16, 2026

GPT-5.6 Terra vs Seed 2.1 Turbo benchmark

Name: GPT-5.6 Terra vs Seed 2.1 Turbo AI benchmark comparison
Creator: CompareLLM
License: https://creativecommons.org/licenses/by/4.0/

This page compares GPT-5.6 Terra (OpenAI) and Seed 2.1 Turbo (ByteDance) using the latest snapshots we have as of Aug 16, 2026. On preference Elo, GPT-5.6 Terra is ahead by 76 points (1,548 vs 1,472; seed-bootstrap (Aug 16, 2026)). On SWE-bench coding, GPT-5.6 Terra resolves 70.4% versus 63.2% (seed-bootstrap (Aug 16, 2026)). Seed 2.1 Turbo streams faster (160 tok/s) while Seed 2.1 Turbo is the cheaper output token ($2.5/1M). GPT-5.6 Terra has the larger context window (1.1M tokens). Every cell below is a dated snapshot from a named public source — we do not invent missing scores, and we do not run SWE-bench ourselves.

Share Analysis:

WhatsApp Telegram X / Post LinkedIn Reddit

OpenAI

GPT-5.6 Terra

OpenAI 5.6 mid tier. Official API $2/$12 per 1M after the Jul 30 2026 price cut.

Elo 1,548$6/1M out

ByteDance

Seed 2.1 Turbo

ByteDance Seed 2.1 Turbo, listed on public model timelines as an Aug 10 2026 API drop.

Elo 1,472$2.5/1M out

Swap or Add Any Model to this Matchup

Instant pairwise benchmark recalculation across 400+ LLMs

Model A

Model B

Quick vs:vs Claude Opus 4.5 vs Claude Opus 4.6 vs Claude Sonnet 4.5 vs Claude 3.7 Sonnet

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

GPT-5.6 Terra (6)vsSeed 2.1 Turbo (4)

GPT-5.6 Terra: 6W (60%)Overall: GPT-5.6 TerraSeed 2.1 Turbo: 4W (40%)

← GPT-5.6 TerraSeed 2.1 Turbo →

GPT-5.6 Terra (5/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,548vs1,472

Coding Elo

1,542vs1,480

SWE-bench

70.4%vs63.2%

LiveBench

69.1%vs64.8%

GPQA Diamond

82%vs76.8%

GPT-5.6 Terra: 5WSeed 2.1 Turbo: 0W

Seed 2.1 Turbo (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

128 tok/svs160 tok/s

Time to first token

160 msvs120 ms

GPT-5.6 Terra: 0WSeed 2.1 Turbo: 2W

Seed 2.1 Turbo (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$6/1Mvs$2.5/1M

Input price

$1/1Mvs$0.5/1M

Context window

1.1Mvs262k

GPT-5.6 Terra: 1WSeed 2.1 Turbo: 2W

Capability Matchup Radar

Multi-Dimensional Capability Radar

Each spoke is a skill. Farther from the center is better (0–100th percentile). Tap any dot to inspect details.

Tap any node to inspect

Percentile 0–100

Dimensional AdvantageGPT-5.6 Terra 4/6

Preference Elo

GPT-5.6 Terra

76 pts advantage

Throughput Speed

Seed 2.1 Turbo

32 tok/s faster

Price Efficiency

Seed 2.1 Turbo

$3.50/1M cheaper

Full Benchmark Score Matrix

—

Elo

High is better

+5%1,548

EloHigh is better

1,472

Code Elo

High is better

+4%1,542

Code EloHigh is better

1,480

LiveBench

High is better

+7%69.1%

LiveBenchHigh is better

64.8%

SWE-bench

High is better

+11%70.4%

SWE-benchHigh is better

63.2%

GPQA

High is better

+7%82%

GPQAHigh is better

76.8%

TTFT

Low is better

160 ms

TTFTLow is better

120 ms+33%

Speed

High is better

128 tok/s

SpeedHigh is better

160 tok/s+25%

In $

Low is better

$1/1M

In $Low is better

$0.5/1M+100%

Out $

Low is better

$6/1M

Out $Low is better

$2.5/1M+140%

Context

High is better

+301%1.1M

ContextHigh is better

262k

Interactive Simulator

Workload Cost & Savings Calculator

Simulate monthly production API costs based on published $/1M tokens.

Save up to 56% with Seed 2.1 Turbo

Monthly Volume50M tokens/mo

Quick Presets:

Token Ratio (In vs Out)70% In / 30% Out

RAG / Search (10% out)Coding / Chat (50% out)

GPT-5.6 Terra$125.00 / mo

In: $35.00Out: $90.00

Seed 2.1 Turbo$55.00 / mo

In: $17.50Out: $37.50

Estimated Cost Delta

Seed 2.1 Turbo is estimated to save $70.00/month ($840/year).

Based on 50M tokens (30% gen)

Key Selection Recommendations

1
GPT-5.6 Terra:Pick GPT-5.6 Terra when repo-level coding accuracy is the constraint.
2
Seed 2.1 Turbo:Pick Seed 2.1 Turbo when you are optimizing output cost.
3
Seed 2.1 Turbo:Pick Seed 2.1 Turbo when time-to-first-token matters more than peak Elo.

Recommended Workload Routing

Repo / coding agentsGPT-5.6 Terra

Higher SWE-bench (70.4%).

High-volume chatSeed 2.1 Turbo

Lower output list price ($2.5/1M).

Voice / low-latency UISeed 2.1 Turbo

Lower TTFT (120 ms).

Long-document RAGGPT-5.6 Terra

Larger window (1.1M).

Screenshots / visionGPT-5.6 Terra

Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	GPT-5.6 Terra	Higher SWE-bench (70.4%).
High-volume chat	Seed 2.1 Turbo	Lower output list price ($2.5/1M).
Voice / low-latency UI	Seed 2.1 Turbo	Lower TTFT (120 ms).
Long-document RAG	GPT-5.6 Terra	Larger window (1.1M).
Screenshots / vision	GPT-5.6 Terra	Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra).

Related Editorial Dispatches & Benchmark Notes

View all news

launchAug 10, 2026

Seed 2.1 Turbo (Aug 10): ByteDance’s API drop on the public timeline

Listed on public model timelines as an Aug 10 2026 API drop. Preview-quality story, indexable because we have a full snapshot.

priceJul 30, 2026

GPT-5.6 Terra after the Jul 30 cut: $2/$12 mid-tier

Terra is OpenAI’s Sonnet-class invoice. Use it when Sol is too expensive and Luna is too small.

Community Sentiment

Cast Your Matchup Vote

0 total votes

Community Discussions (0)

No comments posted on this matchup yet. Be the first to share an evaluation note!

Share card

The real PNG is generated at /compare/gpt-5-6-terra-vs-seed-2-1-turbo/opengraph-image for crawlers.

PNG

CompareLLM Matrix

Verified head-to-head card

LIVE

OpenAI

GPT-5.6 Terra

Elo 1,548

LiveBench69.1%

SWE-bench70.4%

Speed128 tok/s

Output cost$6/1M

ByteDance

Seed 2.1 Turbo

Elo 1,472

LiveBench64.8%

SWE-bench63.2%

Speed160 tok/s

Output cost$2.5/1M

Frequently Asked Questions

Which is better overall, GPT-5.6 Terra or Seed 2.1 Turbo?: GPT-5.6 Terra has the higher preference Elo in our latest snapshot (1,548). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, GPT-5.6 Terra or Seed 2.1 Turbo?: GPT-5.6 Terra leads SWE-bench at 70.4% vs 63.2%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?: Seed 2.1 Turbo output tokens are $2.5/1M versus $6/1M. Input prices and retry rates still move the real bill.
Which is faster, GPT-5.6 Terra or Seed 2.1 Turbo?: Seed 2.1 Turbo has the lower time-to-first-token (120 ms vs 160 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?: GPT-5.6 Terra accepts 1.1M tokens versus 262k.
Can I self-host either model?: Neither model is marked open-weights here. You are comparing hosted APIs.
Are these scores from CompareLLM’s own evals?: No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.
What does preference Elo mean on this page?: Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. GPT-5.6 Terra and Seed 2.1 Turbo Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Similar Head-to-Head Comparisons

All GPT-5.6 Terra matchups →|All Seed 2.1 Turbo matchups →

Seed 2.1 Turbo vs Doubao Pro 1.5 (previous seed)GPT-4.5 Orion vs GPT-5.6 Terra GPT-5 vs GPT-5.6 Terra GPT-5.6 Sol vs GPT-5.6 Terra OpenAI: o3 Mini vs GPT-5.6 Terra OpenAI: o1 vs GPT-5.6 Terra

GPT-5.6 Terra vs Seed 2.1 Turbo benchmark

Interactive Comparison Diagram

Matchup Breakdown

Tug-of-War Matchup Matrix

Category wins across intelligence, speed, and pricing efficiency.

GPT-5.6 Terra (6)vsSeed 2.1 Turbo (4)

GPT-5.6 Terra: 6W (60%)Overall: GPT-5.6 TerraSeed 2.1 Turbo: 4W (40%)

← GPT-5.6 TerraSeed 2.1 Turbo →

GPT-5.6 Terra (5/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Preference Elo

1,548vs1,472

Coding Elo

1,542vs1,480

SWE-bench

70.4%vs63.2%

LiveBench

69.1%vs64.8%

GPQA Diamond

82%vs76.8%

GPT-5.6 Terra: 5WSeed 2.1 Turbo: 0W

Seed 2.1 Turbo (2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Output speed

128 tok/svs160 tok/s

Time to first token

160 msvs120 ms

GPT-5.6 Terra: 0WSeed 2.1 Turbo: 2W

Seed 2.1 Turbo (2/3)

Pricing & Capacity

Cost per million tokens and max context window length

Output price

$6/1Mvs$2.5/1M

Input price

$1/1Mvs$0.5/1M

Context window

1.1Mvs262k

GPT-5.6 Terra: 1WSeed 2.1 Turbo: 2W

Recommended Workload Routing

Repo / coding agentsGPT-5.6 Terra

Higher SWE-bench (70.4%).

High-volume chatSeed 2.1 Turbo

Lower output list price ($2.5/1M).

Voice / low-latency UISeed 2.1 Turbo

Lower TTFT (120 ms).

Long-document RAGGPT-5.6 Terra

Larger window (1.1M).

Screenshots / visionGPT-5.6 Terra

Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra).

Target Workload	Recommended Pick	Evaluation Rationale
Repo / coding agents	GPT-5.6 Terra	Higher SWE-bench (70.4%).
High-volume chat	Seed 2.1 Turbo	Lower output list price ($2.5/1M).
Voice / low-latency UI	Seed 2.1 Turbo	Lower TTFT (120 ms).
Long-document RAG	GPT-5.6 Terra	Larger window (1.1M).
Screenshots / vision	GPT-5.6 Terra	Both accept images. Defaulting to the higher-Elo side (GPT-5.6 Terra).

Frequently Asked Questions

Which is better overall, GPT-5.6 Terra or Seed 2.1 Turbo?

GPT-5.6 Terra has the higher preference Elo in our latest snapshot (1,548). “Better” still depends on coding, price, and latency — see the table.

Which is better at coding, GPT-5.6 Terra or Seed 2.1 Turbo?

GPT-5.6 Terra leads SWE-bench at 70.4% vs 63.2%. SWE-bench is one harness, not your repo.

Which is cheaper to run in production?

Seed 2.1 Turbo output tokens are $2.5/1M versus $6/1M. Input prices and retry rates still move the real bill.

Which is faster, GPT-5.6 Terra or Seed 2.1 Turbo?

Seed 2.1 Turbo has the lower time-to-first-token (120 ms vs 160 ms). Tokens/sec is a separate column if you care about long completions.

Which has the larger context window?

GPT-5.6 Terra accepts 1.1M tokens versus 262k.

Can I self-host either model?

Neither model is marked open-weights here. You are comparing hosted APIs.

Are these scores from CompareLLM’s own evals?

No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.

What does preference Elo mean on this page?

Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. GPT-5.6 Terra and Seed 2.1 Turbo Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Swap or Add Any Model to this Matchup

Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

GPT-5.6 Terra

Seed 2.1 Turbo

Seed 2.1 Turbo

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Seed 2.1 Turbo (Aug 10): ByteDance’s API drop on the public timeline

GPT-5.6 Terra after the Jul 30 cut: $2/$12 mid-tier

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

GPT-5.6 Terra

Seed 2.1 Turbo

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons

Swap or Add Any Model to this Matchup

Interactive Comparison Diagram

Tug-of-War Matchup Matrix

Intelligence & Reasoning

Speed & Latency

Pricing & Capacity

Multi-Dimensional Capability Radar

GPT-5.6 Terra

Seed 2.1 Turbo

Seed 2.1 Turbo

Full Benchmark Score Matrix

Workload Cost & Savings Calculator

Key Selection Recommendations

Recommended Workload Routing

Related Editorial Dispatches & Benchmark Notes

Seed 2.1 Turbo (Aug 10): ByteDance’s API drop on the public timeline

GPT-5.6 Terra after the Jul 30 cut: $2/$12 mid-tier

Cast Your Matchup Vote

Community Discussions (0)

Share card

CompareLLM Matrix

GPT-5.6 Terra

Seed 2.1 Turbo

Frequently Asked Questions

Related news

Similar Head-to-Head Comparisons