Nemotron 3.5 LightningvsGrok 4.20 Beta
Nemotron 3.5 Lightning | Grok 4.20 Beta | |
|---|---|---|
| Specifications | ||
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one. | 30B | — |
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view. | 1M | — |
| API pricingUSD per 1M tokens · lower wins · base tier | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | — | $1.25 |
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one. | — | $2.50 |
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again. | — | $0.20 |
Cheapest inputLowest input rate across third-party providers, excluding the lab itself. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page. | $0.10CoreWeave | — |
Cheapest outputLowest output rate across third-party providers, excluding the lab itself. May come from a different provider than the cheapest input. | $0.25CoreWeave | — |
| Benchmarks | ||
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 51.6% | 76.7% |
| BenchmarksPublished by one model only | ||
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | — | 56% |
ARC-AGI-2Abstract reasoning — Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better. | — | 53.3% |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4% | — |
| Overview | ||
| Company | NVIDIA | SpaceXAI |
| Release date | Aug 11 2026 | Feb 17 2026 |
| Access | Open Source | Proprietary |
Other comparisons
Frequently asked questions
Grok 4.20 Beta leads Nemotron 3.5 Lightning on 1 of the 1 benchmark they both report (SWE-Bench Verified). Only Grok 4.20 Beta has a verified first-party API price: $1.25 per million input tokens and $2.50 per million output tokens. No pay-as-you-go API rate is tracked for Nemotron 3.5 Lightning. Grok 4.20 Beta shipped 175 days before Nemotron 3.5 Lightning, so benchmark comparisons should account for the intervening progress.
Nemotron 3.5 Lightning is open source, while Grok 4.20 Beta is proprietary.
On SWE-Bench Verified, Grok 4.20 Beta leads at 76.7% vs Nemotron 3.5 Lightning at 51.6%.
Nemotron 3.5 Lightning was released by NVIDIA on Aug 11 2026.
Grok 4.20 Beta was released by SpaceXAI on Feb 17 2026.
Grok 4.20 Beta leads on SWE-Bench Verified — Nemotron 3.5 Lightning 51.6% vs Grok 4.20 Beta 76.7%.
Only Grok 4.20 Beta has a verified first-party API price: $1.25 per million input tokens and $2.50 per million output tokens. No pay-as-you-go API rate is tracked for Nemotron 3.5 Lightning. Rates are pay-as-you-go API prices verified on August 18, 2026.
Nemotron 3.5 Lightning is an open source model released by NVIDIA. Grok 4.20 Beta is a proprietary model released by SpaceXAI.