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

Claude Sonnet 5 vs ERNIE 5.1

Claude Sonnet 5 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.

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

Verdict at a glance

Bottom line: Choose Claude Sonnet 5 when coding depth, long-context reliability, lower refusal matter most; choose ERNIE 5.1 when lower cost, fine-tuning/ecosystem is the priority.

Choose Claude Sonnet 5 if you…

  • Fast
  • Moderately priced
  • Anthropic quality
  • Value flagship
  • Best for: Daily tasks, Fast responses, Coding

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.

Claude Sonnet 5 Higher overall
Anthropic · #12 overall
Overall71
Coding73
Multimodal76
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.

DimensionClaude Sonnet 5ERNIE 5.1Verdict
VendorAnthropic (US)Baidu (CN)Different vendors
Released2026.062026.05Claude Sonnet 5 is newer
Overall (rank)71 · #1266 · #17Claude Sonnet 5 +5
Coding73 · #1062 · #18Claude Sonnet 5 +11
Multimodal76 · #1474 · #16Claude Sonnet 5 +2
Context window1M128KClaude Sonnet 5 larger
Max output128K32KERNIE 5.1 longer
Effective-context9582Claude Sonnet 5 more reliable
Input $/1M$3$1.1ERNIE 5.1 cheaper
Output $/1M$15$3.3ERNIE 5.1 cheaper
Cache discount90% offnoneClaude Sonnet 5 deeper
Speed~65 tok/s~45 tok/sClaude Sonnet 5 faster
TTFT0.5s0.7sClaude Sonnet 5 snappier
Function calling8878Claude Sonnet 5 ahead
Refusal rate~8%~12%Claude Sonnet 5 less restrictive
English9065Claude Sonnet 5
Chinese7892ERNIE 5.1
Modalitiestext, imagetext, imageSame
Open weightsNoNoBoth closed
Fine-tuningNoYes
Free tierNo free tierERNIE Bot free; quota on the Qianfan platform
SOC2 / no-trainyes / yesno / yes
Private deploymentNoYesERNIE 5.1

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

Claude Sonnet 5 leads the overall aggregate by 5 points (71 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: Claude Sonnet 5 scores 73 against 62. On multi-file edits, SWE-style tickets and long-horizon agent loops Claude Sonnet 5 needs fewer correction turns; ERNIE 5.1 is still competent for scripts and assisted completion but trails as task complexity rises.

Multimodal

Claude Sonnet 5 leads multimodal 76 vs 74. Neither emits native video, so the comparison is about parsing images and documents, not generation.

Speed & latency

Claude Sonnet 5 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 1M for Claude Sonnet 5 and 128K for ERNIE 5.1. Effective-context scores point the same way as window size — Claude Sonnet 5 is ahead on usable recall (95 vs 82), so prefer it for long-document work where details cannot be missed.

Price & total cost

ERNIE 5.1 is the cheaper API at $1.1/$3.3 versus Claude Sonnet 5 at $3/$15 per 1M input/output tokens — list input is about 2.7× lower. Cache discounts (Claude Sonnet 5 90%) shift the effective bill, worked out below.

Chinese vs English

English: Claude Sonnet 5 90 vs ERNIE 5.1 65. Chinese: 78 vs 92. For Chinese-language production, ERNIE 5.1 is the stronger pick. Note that non-Chinese models generally require overseas network access for their APIs.

Tool use & ecosystem

Function-calling score: Claude Sonnet 5 88 vs ERNIE 5.1 78, so Claude Sonnet 5 has the edge on structured tool use. Fine-tuning is available from 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 monthClaude Sonnet 5ERNIE 5.1Gap
List priceno cache applied$750100M in × $3  +  30M out × $15$209100M in × $1.1  +  30M out × $3.33.59×gap
With caching90% of inputs cache-hit$50790M cached in × $0.3  +  10M in × $3  +  30M out × $15$209no published cache discount2.43×gap

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 Claude Sonnet 5 (coding 73 vs 62).
IF you serve real-time users and latency is a product KPI  →  choose Claude Sonnet 5 (~65 tok/s, 0.5s TTFT).
IF you are cost-driven at scale on routine, high-volume workloads  →  choose ERNIE 5.1 ($$1.1/$$3.3 per 1M in/out).
IF long-document recall has to be near-perfect  →  choose Claude Sonnet 5 (effective context 95 vs 82).
07

Frequently asked questions

Is Claude Sonnet 5 worth the higher price over ERNIE 5.1?
At list the input rate is 2.7x higher, but cache discounts and output pricing narrow the effective gap. Pay the premium when Claude Sonnet 5's stronger dimensions protect revenue; for routine volume ERNIE 5.1 is the economical pick.
How do costs compare at 100M tokens/month with caching?
At 100M input + 30M output with 90% of inputs cache-hit, Claude Sonnet 5 is about $507/month and ERNIE 5.1 about $209/month after cache discounts ($750 and $209 at list).
Does the bigger context window actually matter?
Nominal windows are Claude Sonnet 5 (1M) and ERNIE 5.1 (128K), but usable recall follows the effective-context score (95 vs 82). Prefer the higher effective-context model for long-document work where nothing can be missed.
How do they differ for Chinese-language and data-residency use?
ERNIE 5.1 is the Chinese model (Chinese score 92, domestic cloud, possible private deployment) while Claude Sonnet 5 is the global model (Chinese 78, overseas API). Pick by language quality, access path and where data must reside.
Which one supports fine-tuning?
ERNIE 5.1 supports fine-tuning; Claude Sonnet 5 does not at this tier. If you plan to adapt the model to a narrow domain, that is a concrete differentiator.
What is the single-line recommendation?
Choose Claude Sonnet 5 for Daily tasks, Fast responses; choose ERNIE 5.1 for Chinese, Search-augmented.