NVIDIA Nemotron 3 Super vs Reka Flash 3.1

NVIDIA · US  |  Reka AI · US · Updated June 2026

Quick verdict

Pick NVIDIA Nemotron 3 Super for high-throughput agentic reasoning (up to 2.2x gpt-oss-120b) or 1m-token context with strong long-context retrieval (91.6% ruler @ 1m). Pick Reka Flash 3.1 for a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists) or strong base for fine-tuning agentic tasks - notably improved coding since the original flash 3.

NVIDIA Nemotron 3 Super (NVIDIA) and Reka Flash 3.1 (Reka AI) are two of the models people most often weigh against each other in 2026. NVIDIA Nemotron 3 Super is nVIDIA's open 120B-total/12B-active hybrid Mamba-Transformer MoE built for high-throughput agentic reasoning at 1M-token context. Reka Flash 3.1 is reka AI's compact 21B open-weight reasoning model - small enough to run locally, from a team of DeepMind and Meta alumni. 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

SpecNVIDIA Nemotron 3 SuperReka Flash 3.1
ProviderNVIDIA (US) Reka AI (US)
ReleasedMarch 11, 2026 July 2025
Context window1M (~1,500 pages) 32K (~49 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 Verified60.47% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

High-throughput agentic reasoning (up to 2.2x GPT-OSS-120B)

NVIDIA Nemotron 3 Super

NVIDIA's open 120B-total/12B-active hybrid Mamba-Transformer MoE built for high-throughput agentic reasoning at 1M-token context — and it carries the larger 1M context.

1M-token context with strong long-context retrieval (91.6% RULER @ 1M)

NVIDIA Nemotron 3 Super

Its 1M window holds about 31× more than Reka Flash 3.1's 32K in a single prompt.

Strong math reasoning (90.21% AIME 2025)

NVIDIA Nemotron 3 Super

NVIDIA's open 120B-total/12B-active hybrid Mamba-Transformer MoE built for high-throughput agentic reasoning at 1M-token context — and it is the newer of the two.

A 21B-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists)

Reka Flash 3.1

Reka Flash 3.1 lists a 21B-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists) among its strengths; NVIDIA Nemotron 3 Super does not.

Strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3

Reka Flash 3.1

Reka Flash 3.1 lists strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3 among its strengths; NVIDIA Nemotron 3 Super does not.

Fully open weights (Apache 2.0) from a frontier-caliber research team

Reka Flash 3.1

Reka Flash 3.1 lists fully open weights (Apache 2.0) from a frontier-caliber research team among its strengths; NVIDIA Nemotron 3 Super does not.

Largest single-prompt input

NVIDIA Nemotron 3 Super

Its 1M window is about 31× larger than Reka Flash 3.1's 32K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

Someone analysing very long documents or codebases

NVIDIA Nemotron 3 Super

Larger 1M window fits more in one prompt.

Anyone whose priority is high-throughput agentic reasoning (up to 2.2x gpt-oss-120b)

NVIDIA Nemotron 3 Super

It is specifically built for that.

Anyone whose priority is a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists)

Reka Flash 3.1

That is its strongest area.

NVIDIA Nemotron 3 Super: where it fits

NVIDIA's open 120B-total/12B-active hybrid Mamba-Transformer MoE built for high-throughput agentic reasoning at 1M-token context. Released March 11, 2026 by NVIDIA, it is built for high-throughput agentic reasoning (up to 2.2x GPT-OSS-120B), 1M-token context with strong long-context retrieval (91.6% RULER @ 1M), strong math reasoning (90.21% AIME 2025), and fully open weights, datasets, and recipes for self-hosting.

Its trade-offs are real: text-only; no image, audio, or video input, and requires roughly 8x H100-80GB GPUs to self-host at BF16. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

Reka Flash 3.1: where it fits

Reka AI's compact 21B open-weight reasoning model - small enough to run locally, from a team of DeepMind and Meta alumni. Released July 2025 by Reka AI, it is built for a 21B-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists), strong base for fine-tuning agentic tasks - notably improved coding since the original Flash 3, fully open weights (Apache 2.0) from a frontier-caliber research team, and built by alumni from Google DeepMind and Meta's AI labs.

Its trade-offs: a relatively small 32K context window next to million-token frontier models, smaller and less capable overall than flagship frontier models from major labs, and reka's broader roadmap has shifted toward robotics/world models after merging with Moonvalley in June 2026, raising questions about ongoing LLM investment. As an open-weight model, its running cost is your own hardware rather than a per-token fee.

The bottom line for this matchup

NVIDIA Nemotron 3 Super and Reka Flash 3.1 overlap enough that the right pick depends on your specific job. NVIDIA Nemotron 3 Super holds the larger context; and each leads in its own area — NVIDIA Nemotron 3 Super for high-throughput agentic reasoning (up to 2.2x gpt-oss-120b), Reka Flash 3.1 for a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists). Rather than crowning one, run the same hard task through both once and let the results decide.

Want both NVIDIA Nemotron 3 Super and Reka Flash 3.1 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 NVIDIA Nemotron 3 Super or Reka Flash 3.1 better for coding?

Public SWE-Bench figures are not available for Reka Flash 3.1, so the honest test is your own repository — run an identical real bug through both. By design, NVIDIA Nemotron 3 Super leans toward high-throughput agentic reasoning (up to 2.2x gpt-oss-120b) while Reka Flash 3.1 leans toward a 21b-parameter reasoning model, small enough for local/on-device deployment (a 3.5-bit quantized build exists), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, NVIDIA Nemotron 3 Super or Reka Flash 3.1?

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

Which has the bigger context window?

NVIDIA Nemotron 3 Super — 1M vs 32K, about 31× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both NVIDIA Nemotron 3 Super and Reka Flash 3.1 together?

Yes — a multi-model platform like LumiChats gives you NVIDIA Nemotron 3 Super, Reka Flash 3.1 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, NVIDIA Nemotron 3 Super or Reka Flash 3.1?

NVIDIA Nemotron 3 Super — released March 11, 2026, about 8 months after Reka Flash 3.1.

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.