Claude Opus 5.5 vs ERNIE 5.0

Anthropic · US  |  Baidu · China · Updated June 2026

Quick verdict

Pick Claude Opus 5.5 for performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5 or anthropic reports it surpasses fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning. 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 Opus 5.5 (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 Opus 5.5 is anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching. 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 Opus 5.5ERNIE 5.0
ProviderAnthropic (US) Baidu (China)
ReleasedSeptember 22, 2026 January 22, 2026
Context window1M tokens (~1,500 pages) 128K (~192 pages)
Price (in/out)$4/$20 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 VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Performs at roughly Claude Fable 5.1's level on most work, at 40% lower typical workload cost than Opus 5

Claude Opus 5.5

Anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching — and it carries the larger 1M tokens context.

Anthropic reports it surpasses Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning

Claude Opus 5.5

Anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching — and it is the newer of the two.

Pricing cut to $4/$20 per million tokens (20% below Opus 5's $5/$25), cache reads down 60% to $0.20/MTok

Claude Opus 5.5

Its 1M tokens window holds about 7.8× 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

Claude Opus 5.5 is comparatively weak here — first model in the 5.5 line; Anthropic has signaled Sonnet 5.5 and Haiku 5.5 are still weeks away, so the lower tiers of the family aren't out yet

Particularly strong on Chinese-language reasoning tasks

ERNIE 5.0

Claude Opus 5.5 is comparatively weak here — not a reasoning-ceiling upgrade over Fable 5.1 — pitched as matching its performance at lower cost, not beating it outright

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

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.

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 Opus 5.5

Its 1M tokens window is about 7.8× larger than ERNIE 5.0's 128K, fitting roughly 1,500 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 Opus 5.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Opus 5.5

Larger 1M tokens window fits more in one prompt.

Anyone whose priority is performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5

Claude Opus 5.5

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 Opus 5.5 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 Opus 5.5: where it fits

Anthropic's September 22, 2026 update: Fable 5.1-level performance at 40% lower cost than Opus 5, with faster output and cheaper caching. Released September 22, 2026 by Anthropic, it is built for performs at roughly Claude Fable 5.1's level on most work, at 40% lower typical workload cost than Opus 5, anthropic reports it surpasses Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning, pricing cut to $4/$20 per million tokens (20% below Opus 5's $5/$25), cache reads down 60% to $0.20/MTok, and output speed increased over 30% versus Opus 5.

Its trade-offs are real: not a reasoning-ceiling upgrade over Fable 5.1 — pitched as matching its performance at lower cost, not beating it outright, like Opus 5, the headline 1M-token context is not uniformly available across every platform and plan — some API paths default to a smaller window, and first model in the 5.5 line; Anthropic has signaled Sonnet 5.5 and Haiku 5.5 are still weeks away, so the lower tiers of the family aren't out yet. At $4 in / $20 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 Opus 5.5 (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 Opus 5.5 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 Opus 5.5 or ERNIE 5.0 better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 5.5 leans toward performs at roughly claude fable 5.1's level on most work, at 40% lower typical workload cost than opus 5 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 Opus 5.5 or ERNIE 5.0?

ERNIE 5.0 is cheaper — $4/$20 per 1M tokens vs $0.6/$2.1 per 1M tokens, roughly 6.7× apart on input.

Which has the bigger context window?

Claude Opus 5.5 — 1M tokens vs 128K, about 7.8× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Opus 5.5 and ERNIE 5.0 together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 5.5, 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 Opus 5.5 or ERNIE 5.0?

Claude Opus 5.5 — released September 22, 2026, about 8 months after ERNIE 5.0.

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.