Jamba2 Mini vs NVIDIA Nemotron 3 Ultra

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

Quick verdict

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. Pick NVIDIA Nemotron 3 Ultra for the most capable open-weight model from a us lab (artificial analysis intelligence index of about 48) or fast, efficient long-horizon agentic reasoning via a hybrid mamba-transformer design.

Jamba2 Mini (AI21 Labs, Israel) and NVIDIA Nemotron 3 Ultra (NVIDIA, US) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. 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. NVIDIA Nemotron 3 Ultra is nVIDIA's open-weight reasoning flagship (about 550B total, 55B active) — the most capable open model from a US lab, built for long-running agents. Their biggest split is context window, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecJamba2 MiniNVIDIA Nemotron 3 Ultra
ProviderAI21 Labs (Israel) NVIDIA (US)
ReleasedJanuary 8, 2026 June 4, 2026
Context window256K (~393 pages) 1M (~1,500 pages)
Price (in/out)Open weight (self-host / free) Open weight (self-host / free)
Open weight?Yes — self-hostable Yes — self-hostable
Modalitiestext, code text, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

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

Jamba2 Mini

Jamba2 Mini lists a genuinely different architecture - hybrid Mamba (SSM) + Transformer, not another transformer variant among its strengths; NVIDIA Nemotron 3 Ultra does not.

Fast, efficient long-context inference tuned for enterprise workloads

Jamba2 Mini

NVIDIA Nemotron 3 Ultra is comparatively weak here — a 550B mixture-of-experts is heavy to self-host, and the 1M context is rarely served in full

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

Jamba2 Mini

Jamba2 Mini lists open weights (Apache 2.0) - free to self-host among its strengths; NVIDIA Nemotron 3 Ultra does not.

The most capable open-weight model from a US lab (Artificial Analysis Intelligence Index of about 48)

NVIDIA Nemotron 3 Ultra

NVIDIA's open-weight reasoning flagship (about 550B total, 55B active) — the most capable open model from a US lab, built for long-running agents — and it carries the larger 1M context.

Fast, efficient long-horizon agentic reasoning via a hybrid Mamba-Transformer design

NVIDIA Nemotron 3 Ultra

Its 1M window holds about 3.8× more than Jamba2 Mini's 256K in a single prompt.

A fully open release — weights, training data, and recipes under a permissive license

NVIDIA Nemotron 3 Ultra

NVIDIA's open-weight reasoning flagship (about 550B total, 55B active) — the most capable open model from a US lab, built for long-running agents — and it is the newer of the two.

Largest single-prompt input

NVIDIA Nemotron 3 Ultra

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?

Someone analysing very long documents or codebases

NVIDIA Nemotron 3 Ultra

Larger 1M window fits more in one prompt.

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

Jamba2 Mini

It is specifically built for that.

Anyone whose priority is the most capable open-weight model from a us lab (artificial analysis intelligence index of about 48)

NVIDIA Nemotron 3 Ultra

That is its strongest area.

An enterprise with regional data-residency rules

NVIDIA Nemotron 3 Ultra or Jamba2 Mini

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

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 are real: 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.

NVIDIA Nemotron 3 Ultra: where it fits

NVIDIA's open-weight reasoning flagship (about 550B total, 55B active) — the most capable open model from a US lab, built for long-running agents. Released June 4, 2026 by NVIDIA, it is built for the most capable open-weight model from a US lab (Artificial Analysis Intelligence Index of about 48), fast, efficient long-horizon agentic reasoning via a hybrid Mamba-Transformer design, a fully open release — weights, training data, and recipes under a permissive license, and strong coding for an open model (SWE-Bench Verified in the high 60s).

Its trade-offs: trails the best Chinese open models on overall intelligence, and a 550B mixture-of-experts is heavy to self-host, and the 1M context is rarely served in full. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

This is less "which is smarter" and more "which ecosystem fits." Jamba2 Mini (Israel) and NVIDIA Nemotron 3 Ultra (US) differ on pricing philosophy, data-residency, and tooling as much as on raw scores. 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 Jamba2 Mini and NVIDIA Nemotron 3 Ultra 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 Jamba2 Mini or NVIDIA Nemotron 3 Ultra 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, Jamba2 Mini leans toward a genuinely different architecture - hybrid mamba (ssm) + transformer, not another transformer variant while NVIDIA Nemotron 3 Ultra leans toward the most capable open-weight model from a us lab (artificial analysis intelligence index of about 48), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Jamba2 Mini or NVIDIA Nemotron 3 Ultra?

They are priced almost identically, so cost will not decide between them.

Which has the bigger context window?

NVIDIA Nemotron 3 Ultra — 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 Jamba2 Mini and NVIDIA Nemotron 3 Ultra together?

Yes — a multi-model platform like LumiChats gives you Jamba2 Mini, NVIDIA Nemotron 3 Ultra 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, Jamba2 Mini or NVIDIA Nemotron 3 Ultra?

NVIDIA Nemotron 3 Ultra — released June 4, 2026, about 5 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.