Grok 4.3 vs Jamba2 Mini

xAI · US  |  AI21 Labs · Israel · Updated June 2026

Quick verdict

Pick Grok 4.3 for video understanding from native video input or generating pdf, pptx, and xlsx files directly. Pick Jamba2 Mini for a genuinely different architecture - hybrid mamba (ssm) + transformer, not another transformer variant or fast, efficient long-context inference tuned for enterprise workloads. Choose Jamba2 Mini if you need self-hosting or data privacy; Grok 4.3 if you want a managed API.

Grok 4.3 (xAI, US) and Jamba2 Mini (AI21 Labs, Israel) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. Grok 4.3 is the current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Jamba2 Mini is aI21's hybrid Mamba-Transformer model - a genuinely different architecture built for fast, efficient long-context enterprise work, free to self-host under Apache 2.0. 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 4.3Jamba2 Mini
ProviderxAI (US) AI21 Labs (Israel)
ReleasedApril 30, 2026 January 8, 2026
Context window1M (~1,500 pages) 256K (~393 pages)
Price (in/out)$1.25/$2.5 per 1M tokens Open weight (self-host / free)
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, video, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Video understanding from native video input

Grok 4.3

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5 — and it carries the larger 1M context.

Generating PDF, PPTX, and XLSX files directly

Grok 4.3

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5 — and it is the newer of the two.

Real-time questions using live X data

Grok 4.3

Grok 4.3 lists real-time questions using live X data among its strengths; Jamba2 Mini does not.

A genuinely different architecture - hybrid Mamba (SSM) + Transformer, not another transformer variant

Jamba2 Mini

AI21's hybrid Mamba-Transformer model - a genuinely different architecture built for fast, efficient long-context enterprise work, free to self-host under Apache 2.0 — and its weights are open while Grok 4.3 is API-only.

Fast, efficient long-context inference tuned for enterprise workloads

Jamba2 Mini

Grok 4.3 is comparatively weak here — higher context pricing on requests above 200K tokens

Open weights (Apache 2.0) - free to self-host

Jamba2 Mini

Open weights make this possible at all — Grok 4.3 is API-only, so it cannot leave the vendor's servers.

Lowest cost at scale

Jamba2 Mini

Its weights are open, so at volume you pay for your own hardware instead of Grok 4.3's $1.25/$2.5 per 1M tokens.

Largest single-prompt input

Grok 4.3

Its 1M window is about 3.8× larger than Jamba2 Mini's 256K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Jamba2 Mini

At Open weight (self-host / free) it undercuts Grok 4.3, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.3

Larger 1M window fits more in one prompt.

A team with data-privacy or self-hosting needs

Jamba2 Mini

Open weights let you run it on your own hardware; Grok 4.3 is API-only.

Anyone whose priority is video understanding from native video input

Grok 4.3

It is specifically built for that.

Anyone whose priority is a genuinely different architecture - hybrid mamba (ssm) + transformer, not another transformer variant

Jamba2 Mini

That is its strongest area.

An enterprise with regional data-residency rules

Grok 4.3 or Jamba2 Mini

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

Grok 4.3: where it fits

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Released April 30, 2026 by xAI, it is built for video understanding from native video input, generating PDF, PPTX, and XLSX files directly, real-time questions using live X data, and long-context, multi-agent reasoning.

Its trade-offs are real: higher context pricing on requests above 200K tokens, and less independent benchmark coverage than OpenAI, Anthropic, or Google. At $1.25 in / $2.5 out per million tokens, it sits in the mid price band.

Jamba2 Mini: where it fits

AI21's hybrid Mamba-Transformer model - a genuinely different architecture built for fast, efficient long-context enterprise work, free to self-host under Apache 2.0. Released January 8, 2026 by AI21 Labs, it is built for a genuinely different architecture - hybrid Mamba (SSM) + Transformer, not another transformer variant, fast, efficient long-context inference tuned for enterprise workloads, open weights (Apache 2.0) - free to self-host, and a 52B-total/12B-active MoE design that's cheap to run relative to its capability.

Its trade-offs: tuned for grounded, steerable enterprise tasks rather than topping general reasoning leaderboards, no official per-token API price published - self-host or use AI21's platform preview, and newer architecture family means less third-party tooling support than mainstream transformers. 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. Jamba2 Mini gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Grok 4.3 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 4.3 and Jamba2 Mini 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 4.3 or Jamba2 Mini 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 4.3 leans toward video understanding from native video input while Jamba2 Mini leans toward a genuinely different architecture - hybrid mamba (ssm) + transformer, not another transformer variant, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Grok 4.3 or Jamba2 Mini?

Jamba2 Mini is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Grok 4.3 is API-metered at $1.25/$2.5 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 4.3 — 1M vs 256K, about 3.8× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Grok 4.3 and Jamba2 Mini together?

Yes — a multi-model platform like LumiChats gives you Grok 4.3, Jamba2 Mini 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 4.3 or Jamba2 Mini?

Grok 4.3 — released April 30, 2026, about 4 months after Jamba2 Mini.

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.