Grok 4.5 vs LongCat-2.0

xAI · US  |  Meituan · China · Updated June 2026

Quick verdict

Pick Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost or extreme token efficiency — around 4x fewer output tokens per task than opus 4.8. Pick LongCat-2.0 for near-frontier agentic coding — topped openrouter anonymously as 'owl alpha' for two months or massive native 1m context at near-linear cost via sparse attention. Choose LongCat-2.0 if you need self-hosting or data privacy; Grok 4.5 if you want a managed API.

Grok 4.5 (xAI, US) and LongCat-2.0 (Meituan, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. Grok 4.5 is xAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. LongCat-2.0 is a trillion-parameter, MIT-licensed open MoE delivering near-frontier agentic coding at 1M context — trained entirely on Chinese chips. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGrok 4.5LongCat-2.0
ProviderxAI (US) Meituan (China)
ReleasedJuly 8, 2026 July 5, 2026
Context window500K (~750 pages) 1M (~1,500 pages)
Price (in/out)$2/$6 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost

Grok 4.5

A core design strength of Grok 4.5.

Extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8

Grok 4.5

A core design strength of Grok 4.5.

In-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor

Grok 4.5

A core design strength of Grok 4.5.

Near-frontier agentic coding — topped OpenRouter anonymously as 'Owl Alpha' for two months

LongCat-2.0

A core design strength of LongCat-2.0.

Massive native 1M context at near-linear cost via sparse attention

LongCat-2.0

A core design strength of LongCat-2.0.

Fully MIT-licensed 1.6T-parameter mixture-of-experts (about 48B active)

LongCat-2.0

A core design strength of LongCat-2.0.

Lowest cost at scale

LongCat-2.0

At Open weight (self-host / free), it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

LongCat-2.0

Its 1M window is about 2× larger, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

LongCat-2.0

At Open weight (self-host / free) it undercuts Grok 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

LongCat-2.0

Larger 1M window fits more in one prompt.

A team with data-privacy or self-hosting needs

LongCat-2.0

Open weights let you run it on your own hardware; Grok 4.5 is API-only.

Anyone whose priority is cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost

Grok 4.5

It is specifically built for that.

Anyone whose priority is near-frontier agentic coding — topped openrouter anonymously as 'owl alpha' for two months

LongCat-2.0

That is its strongest area.

An enterprise with regional data-residency rules

Grok 4.5 or LongCat-2.0

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

Grok 4.5: where it fits

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. Released July 8, 2026 by xAI, it is built for cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost, extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8, in-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor, and top-tier placement on the Artificial Analysis Intelligence Index.

Its trade-offs are real: smaller 500K context (halved from the 1M generation), with pricing that doubles above 200K tokens, and eU launch delayed; no open weights. At $2 in / $6 out per million tokens, it sits in the mid price band.

LongCat-2.0: where it fits

A trillion-parameter, MIT-licensed open MoE delivering near-frontier agentic coding at 1M context — trained entirely on Chinese chips. Released July 5, 2026 by Meituan, it is built for near-frontier agentic coding — topped OpenRouter anonymously as 'Owl Alpha' for two months, massive native 1M context at near-linear cost via sparse attention, fully MIT-licensed 1.6T-parameter mixture-of-experts (about 48B active), and trained end to end on domestic Chinese chips, independent of Nvidia hardware.

Its trade-offs: a 1.6T model is extremely expensive to self-host, so most use leans on the China-hosted API, and headline scores are vendor-reported on SWE-Bench Pro, not the Verified set. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

The defining split here is open vs. closed. LongCat-2.0 gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Grok 4.5 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both Grok 4.5 and LongCat-2.0 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 Grok 4.5 or LongCat-2.0 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, Grok 4.5 leans toward cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost while LongCat-2.0 leans toward near-frontier agentic coding — topped openrouter anonymously as 'owl alpha' for two months, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Grok 4.5 or LongCat-2.0?

LongCat-2.0 is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Grok 4.5 is API-metered at $2/$6 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

LongCat-2.0 — 1M vs 500K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Grok 4.5 and LongCat-2.0 together?

Yes — a multi-model platform like LumiChats gives you Grok 4.5, LongCat-2.0 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, Grok 4.5 or LongCat-2.0?

Grok 4.5 — released July 8, 2026, about 3 days after LongCat-2.0.

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.