Grok 4.5 vs Qwen3.8-Flash-Next

xAI · US  |  Alibaba · 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 Qwen3.8-Flash-Next for swe-bench pro (62.5, ahead of claude opus 4.6 max's 53.4) or cost efficiency: ~1/9th the training cost of qwen3.7-plus, ~12x cheaper api than flagship qwen3.8-max. Choose Qwen3.8-Flash-Next if you need self-hosting or data privacy; Grok 4.5 if you want a managed API.

Grok 4.5 (xAI, US) and Qwen3.8-Flash-Next (Alibaba, 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. Qwen3.8-Flash-Next is alibaba's open-weight preview of its next-generation Qwen4 hybrid-attention architecture, released August 26, 2026 as a 125B-parameter (6B active) MoE model priced roughly 12x below its own flagship Qwen3.8-Max. 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 4.5Qwen3.8-Flash-Next
ProviderxAI (US) Alibaba (China)
ReleasedJuly 8, 2026 August 26, 2026
Context window500K (~750 pages) 262K tokens natively (extensible to 1M with YaRN) (~393 pages)
Price (in/out)$2/$6 per 1M tokens $0.16/$0.47 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, video
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

Its 500K window holds about 1.9× more than Qwen3.8-Flash-Next's 262K tokens natively (extensible to 1M with YaRN) in a single prompt.

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

Grok 4.5

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex — and it carries the larger 500K context.

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

Grok 4.5

Grok 4.5 lists in-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor among its strengths; Qwen3.8-Flash-Next does not.

SWE-bench Pro (62.5, ahead of Claude Opus 4.6 Max's 53.4)

Qwen3.8-Flash-Next

Alibaba's open-weight preview of its next-generation Qwen4 hybrid-attention architecture, released August 26, 2026 as a 125B-parameter (6B active) MoE model priced roughly 12x below its own flagship Qwen3.8-Max — and it runs cheaper at $0.16/$0.47 per 1M tokens.

Cost efficiency: ~1/9th the training cost of Qwen3.7-Plus, ~12x cheaper API than flagship Qwen3.8-Max

Qwen3.8-Flash-Next

At $0.16/$0.47 per 1M tokens it undercuts Grok 4.5 ($2/$6 per 1M tokens), and that gap compounds at volume.

Vision-based agentic tasks (AndroidWorld: 84.5)

Qwen3.8-Flash-Next

Alibaba's open-weight preview of its next-generation Qwen4 hybrid-attention architecture, released August 26, 2026 as a 125B-parameter (6B active) MoE model priced roughly 12x below its own flagship Qwen3.8-Max — and its weights are open while Grok 4.5 is API-only.

Lowest cost at scale

Qwen3.8-Flash-Next

At $0.16/$0.47 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Grok 4.5

Its 500K window is about 1.9× larger than Qwen3.8-Flash-Next's 262K tokens natively (extensible to 1M with YaRN), fitting roughly 750 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Qwen3.8-Flash-Next

At $0.16/$0.47 per 1M tokens it undercuts Grok 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.5

Larger 500K window fits more in one prompt.

A team with data-privacy or self-hosting needs

Qwen3.8-Flash-Next

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 swe-bench pro (62.5, ahead of claude opus 4.6 max's 53.4)

Qwen3.8-Flash-Next

That is its strongest area.

An enterprise with regional data-residency rules

Grok 4.5 or Qwen3.8-Flash-Next

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.

Qwen3.8-Flash-Next: where it fits

Alibaba's open-weight preview of its next-generation Qwen4 hybrid-attention architecture, released August 26, 2026 as a 125B-parameter (6B active) MoE model priced roughly 12x below its own flagship Qwen3.8-Max. Released August 26, 2026 by Alibaba, it is built for sWE-bench Pro (62.5, ahead of Claude Opus 4.6 Max's 53.4), cost efficiency: ~1/9th the training cost of Qwen3.7-Plus, ~12x cheaper API than flagship Qwen3.8-Max, vision-based agentic tasks (AndroidWorld: 84.5), and previews Qwen4's hybrid gated-DeltaNet plus sparse-attention architecture.

Its trade-offs: trails Claude Opus 4.6 Max on Humanity's Last Exam (35.9 vs 40.0), lower OSWorld 2.0 binary success rate (19.4%), and an open-weight architecture preview rather than Alibaba's polished flagship product. At $0.16 in / $0.47 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

The defining split here is open vs. closed. Qwen3.8-Flash-Next 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 Qwen3.8-Flash-Next 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 Qwen3.8-Flash-Next 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 Qwen3.8-Flash-Next leans toward swe-bench pro (62.5, ahead of claude opus 4.6 max's 53.4), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Grok 4.5 or Qwen3.8-Flash-Next?

Qwen3.8-Flash-Next 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?

Grok 4.5 — 500K vs 262K tokens natively (extensible to 1M with YaRN), about 1.9× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Grok 4.5 and Qwen3.8-Flash-Next together?

Yes — a multi-model platform like LumiChats gives you Grok 4.5, Qwen3.8-Flash-Next 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 Qwen3.8-Flash-Next?

Qwen3.8-Flash-Next — released August 26, 2026, about 49 days after Grok 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.