Claude Sonnet 4.5 vs ERNIE 5.0

Anthropic · US  |  Baidu · China · Updated June 2026

Quick verdict

Pick Claude Sonnet 4.5 for agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch or computer use and gui automation (61.4% osworld at launch). Pick ERNIE 5.0 for baidu's flagship omni-modal model — text, image and video understanding or particularly strong on chinese-language reasoning tasks. On a tight budget at scale, ERNIE 5.0 is the value pick.

Claude Sonnet 4.5 (Anthropic, US) and ERNIE 5.0 (Baidu, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. Claude Sonnet 4.5 is september 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. ERNIE 5.0 is baidu's flagship omni-modal ERNIE model — strong Chinese-language and multimodal reasoning at low cost, though it trails the Western frontier on independent benchmarks. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Sonnet 4.5ERNIE 5.0
ProviderAnthropic (US) Baidu (China)
ReleasedSeptember 29, 2025 January 22, 2026
Context window200K (~300 pages) 128K (~192 pages)
Price (in/out)$3/$15 per 1M tokens $0.6/$2.1 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, video, code
SWE-Bench Verified77.2% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch

Claude Sonnet 4.5

September 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded — and it carries the larger 200K context.

Computer use and GUI automation (61.4% OSWorld at launch)

Claude Sonnet 4.5

Claude Sonnet 4.5 lists computer use and GUI automation (61.4% OSWorld at launch) among its strengths; ERNIE 5.0 does not.

Long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks

Claude Sonnet 4.5

Its 200K window holds about 1.6× more than ERNIE 5.0's 128K in a single prompt.

Baidu's flagship omni-modal model — text, image and video understanding

ERNIE 5.0

Baidu's flagship omni-modal ERNIE model — strong Chinese-language and multimodal reasoning at low cost, though it trails the Western frontier on independent benchmarks — and it runs cheaper at $0.6/$2.1 per 1M tokens.

Particularly strong on Chinese-language reasoning tasks

ERNIE 5.0

Baidu's flagship omni-modal ERNIE model — strong Chinese-language and multimodal reasoning at low cost, though it trails the Western frontier on independent benchmarks — and it is the newer of the two.

Competitive API pricing (around $0.60/$2.10 per million tokens)

ERNIE 5.0

ERNIE 5.0 lists competitive API pricing (around $0.60/$2.10 per million tokens) among its strengths; Claude Sonnet 4.5 does not.

Lowest cost at scale

ERNIE 5.0

At $0.6/$2.1 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Claude Sonnet 4.5

Its 200K window is about 1.6× larger than ERNIE 5.0's 128K, fitting roughly 300 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

ERNIE 5.0

At $0.6/$2.1 per 1M tokens it undercuts Claude Sonnet 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Sonnet 4.5

Larger 200K window fits more in one prompt.

Anyone whose priority is agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch

Claude Sonnet 4.5

It is specifically built for that.

Anyone whose priority is baidu's flagship omni-modal model — text, image and video understanding

ERNIE 5.0

That is its strongest area.

An enterprise with regional data-residency rules

Claude Sonnet 4.5 or ERNIE 5.0

Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.

Claude Sonnet 4.5: where it fits

September 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. Released September 29, 2025 by Anthropic, it is built for agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch, computer use and GUI automation (61.4% OSWorld at launch), long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks, and tracking its own remaining token budget natively, which few models do.

Its trade-offs are real: superseded twice — Sonnet 4.6 and Sonnet 5 match or beat it at the same or lower price, capped at 200K since Anthropic retired its 1M beta in April 2026, while its successors ship 1M as standard, and missing the modern API surface: no adaptive thinking, no effort control, and half the max output of newer Sonnets. At $3 in / $15 out per million tokens, it sits in the mid price band.

ERNIE 5.0: where it fits

Baidu's flagship omni-modal ERNIE model — strong Chinese-language and multimodal reasoning at low cost, though it trails the Western frontier on independent benchmarks. Released January 22, 2026 by Baidu, it is built for baidu's flagship omni-modal model — text, image and video understanding, particularly strong on Chinese-language reasoning tasks, competitive API pricing (around $0.60/$2.10 per million tokens), and backed by a major lab with deep China-market integration.

Its trade-offs: trails the Western frontier on aggregate independent tests (AA Intelligence Index ~22 for the tracked Thinking Preview), parameter and architecture details are vendor-stated and opaque, closed weights on a China-hosted API, and 128K context is smaller than 1M-token rivals. At $0.6 in / $2.1 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

This is less "which is smarter" and more "which ecosystem fits." Claude Sonnet 4.5 (US) and ERNIE 5.0 (China) differ on pricing philosophy, data-residency, and tooling as much as on raw scores. ERNIE 5.0 is the cheaper option, which matters at volume. The pragmatic move is to run one real task through both and judge the outputs against your own constraints — including where your data is allowed to be processed.

Want both Claude Sonnet 4.5 and ERNIE 5.0 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Claude Sonnet 4.5 or ERNIE 5.0 better for coding?

Public SWE-Bench figures are not available for ERNIE 5.0, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 4.5 leans toward agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch while ERNIE 5.0 leans toward baidu's flagship omni-modal model — text, image and video understanding, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Sonnet 4.5 or ERNIE 5.0?

ERNIE 5.0 is cheaper — $3/$15 per 1M tokens vs $0.6/$2.1 per 1M tokens, roughly 5× apart on input.

Which has the bigger context window?

Claude Sonnet 4.5 — 200K vs 128K, about 1.6× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Sonnet 4.5 and ERNIE 5.0 together?

Yes — a multi-model platform like LumiChats gives you Claude Sonnet 4.5, ERNIE 5.0 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Claude Sonnet 4.5 or ERNIE 5.0?

ERNIE 5.0 — released January 22, 2026, about 4 months after Claude Sonnet 4.5.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.