MModelspectraIndependent AI Model Intelligence
Head-to-head · Updated 2026-09-08
Model Comparison · Head to Head

Doubao Seed 2.1 Pro vs ERNIE 5.1

Doubao Seed 2.1 Pro 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.

VendorByteDance / Baidu
Data fields15+ dimensions
Updated2026-09-08
Read~9 min
01

Verdict at a glance

Bottom line: Choose Doubao Seed 2.1 Pro when coding depth, long-context reliability, lower refusal matter most; choose ERNIE 5.1 when its stronger dimensions is the priority.

Choose Doubao Seed 2.1 Pro if you…

  • World-leading video understanding
  • Excellent Chinese
  • Strong agent ability
  • Full 256K context
  • Best for: Video understanding, Chinese tasks, AI agents

Choose ERNIE 5.1 if you…

  • Optimized for Chinese
  • Search augmentation
  • Baidu integration
  • Mature enterprise services
  • Best for: Chinese, Search-augmented, Enterprise services
02

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.

Doubao Seed 2.1 Pro Higher overall
ByteDance · #7 overall
Overall78
Coding76
Multimodal92
VS
ERNIE 5.1
Baidu · #17 overall
Overall66
Coding62
Multimodal74

Aggregated from public sources and independently weighted; methodology on the Terms page. Scores within 3 points are treated as statistically tied.

03

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.

DimensionDoubao Seed 2.1 ProERNIE 5.1Verdict
VendorByteDance (CN)Baidu (CN)Different vendors
Released2026.062026.05Doubao Seed 2.1 Pro is newer
Overall (rank)78 · #766 · #17Doubao Seed 2.1 Pro +12
Coding76 · #762 · #18Doubao Seed 2.1 Pro +14
Multimodal92 · #274 · #16Doubao Seed 2.1 Pro +18
Context window256K128KDoubao Seed 2.1 Pro larger
Max output256K32KERNIE 5.1 longer
Effective-context9382Doubao Seed 2.1 Pro more reliable
Input $/1M$0.83$1.1Doubao Seed 2.1 Pro cheaper
Output $/1M$4.17$3.3ERNIE 5.1 cheaper
Cache discountcustomnoneERNIE 5.1 deeper
Speed~65 tok/s~45 tok/sDoubao Seed 2.1 Pro faster
TTFT0.5s0.7sDoubao Seed 2.1 Pro snappier
Function calling8578Doubao Seed 2.1 Pro ahead
Refusal rate~11%~12%Doubao Seed 2.1 Pro less restrictive
English7265Doubao Seed 2.1 Pro
Chinese9592Doubao Seed 2.1 Pro
Modalitiestext, image, videotext, imagedifferent coverage
Open weightsNoNoBoth closed
Fine-tuningYesYes
Free tierDoubao App free; free quota on the Ark platformERNIE Bot free; quota on the Qianfan platform
SOC2 / no-trainno / yesno / yes
Private deploymentYesYesBoth support it

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.

04

Dimension-by-dimension analysis

Reasoning & overall intelligence

Doubao Seed 2.1 Pro leads the overall aggregate by 12 points (78 vs 66). That is a meaningful, not marginal, edge on hard, multi-step reasoning, while ERNIE 5.1 remains a strong generalist that is not out of its depth on routine work.

Agentic coding

This is a clear gap: Doubao Seed 2.1 Pro scores 76 against 62. On multi-file edits, SWE-style tickets and long-horizon agent loops Doubao Seed 2.1 Pro needs fewer correction turns; ERNIE 5.1 is still competent for scripts and assisted completion but trails as task complexity rises.

Multimodal

Doubao Seed 2.1 Pro leads multimodal 92 vs 74. A concrete modality difference: Doubao Seed 2.1 Pro additionally handles video.

Speed & latency

Doubao Seed 2.1 Pro is faster in interactive use: ~65 tok/s with 0.5s TTFT versus ~45 tok/s with 0.7s TTFT (about 1.4× 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 256K for Doubao Seed 2.1 Pro and 128K for ERNIE 5.1. Effective-context scores point the same way as window size — Doubao Seed 2.1 Pro is ahead on usable recall (93 vs 82), so prefer it for long-document work where details cannot be missed.

Price & total cost

Doubao Seed 2.1 Pro is the cheaper API at $0.83/$4.17 versus ERNIE 5.1 at $1.1/$3.3 per 1M input/output tokens — list input is about 1.3× lower.

Chinese vs English

English: Doubao Seed 2.1 Pro 72 vs ERNIE 5.1 65. Chinese: 95 vs 92. For Chinese-language production, Doubao Seed 2.1 Pro is the stronger pick. Note that non-Chinese models generally require overseas network access for their APIs.

Tool use & ecosystem

Function-calling score: Doubao Seed 2.1 Pro 85 vs ERNIE 5.1 78, so Doubao Seed 2.1 Pro has the edge on structured tool use. Fine-tuning is available from Doubao Seed 2.1 Pro and ERNIE 5.1. Factor in existing SDK/plugin familiarity — switching cost often outweighs a few-point tool-use gap.

05

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 monthDoubao Seed 2.1 ProERNIE 5.1Gap
List priceno cache applied$208100M in × $0.83  +  30M out × $4.17$209100M in × $1.1  +  30M out × $3.31.00×even
With caching90% of inputs cache-hit$208no published cache discount$209no published cache discount1.00×even

Illustrative model; your input/output mix and cache-hit ratio change the result. Prices are list rates before any enterprise agreement.

06

Decision tree

IF the workload is agentic or multi-file coding and a wrong first pass is expensive  →  choose Doubao Seed 2.1 Pro (coding 76 vs 62).
IF you serve real-time users and latency is a product KPI  →  choose Doubao Seed 2.1 Pro (~65 tok/s, 0.5s TTFT).
IF you are cost-driven at scale on routine, high-volume workloads  →  choose Doubao Seed 2.1 Pro ($$0.83/$$4.17 per 1M in/out).
IF long-document recall has to be near-perfect  →  choose Doubao Seed 2.1 Pro (effective context 93 vs 82).
07

Frequently asked questions

Which is better for agentic coding?
Doubao Seed 2.1 Pro is decisively stronger for coding (76 vs 62 on the aggregate). The gap shows on SWE-style multi-file tasks and long agent loops that need fewer correction turns; ERNIE 5.1 is fine for routine scripts.
How do costs compare at 100M tokens/month with caching?
At 100M input + 30M output with 90% of inputs cache-hit, Doubao Seed 2.1 Pro is about $208/month and ERNIE 5.1 about $209/month after cache discounts ($208 and $209 at list).
Does the bigger context window actually matter?
Nominal windows are Doubao Seed 2.1 Pro (256K) and ERNIE 5.1 (128K), but usable recall follows the effective-context score (93 vs 82). Prefer the higher effective-context model for long-document work where nothing can be missed.
Which handles multimodal inputs better?
Multimodal scores are 92 (Doubao Seed 2.1 Pro) vs 74 (ERNIE 5.1), with modality coverage text/image/video versus text/image. Match the model to the input types your product actually receives.
What is the single-line recommendation?
Choose Doubao Seed 2.1 Pro for Video understanding, Chinese tasks; choose ERNIE 5.1 for Chinese, Search-augmented.
How quickly do these rankings change?
Modelspectra refreshes the aggregate as new public benchmarks and prices appear. Treat scores within 3 points as a tie and re-check before a committed purchase.