Nex-N2.5-Mini (free) is cheaper than Step 5 Preview at $0/M vs $1/M input tokens.
The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.
Nex-N2.5-Mini (free): A 1920 transistor would not by itself prevent fascism, the Great Depression, or imperial expansion, so World War II might still happen. But it would make electronics 10–20 years more advanced than in our timeline, with huge effects on radar, codebreaking, computing, missiles, space, consumer goods, and Cold War power…
Step 5 Preview: Assume the 1920 invention is not a fragile lab curiosity but a manufacturable solid-state amplifier/switch by the mid-1920s. Vacuum tubes still dominate high-power RF transmission into the 1950s, but receivers, switching logic, control systems, and computers move to solid state decades early.
Three-month biohacker protocol, with dosages and biomarkers named.
Nex-N2.5-Mini (free): Below is a 12-week longevity/performance protocol for a generally healthy adult. It is not medical advice. Before starting—especially if you have diabetes, hypertension, arrhythmia, kidney/liver disease, a history of eating disorders, are pregnant, or take medications—get clinician clearance and use labs to personalize…
Step 5 Preview: IMPORTANT MEDICAL DISCLAIMER: This is an educational framework for informational purposes only. It is not medical advice, diagnosis, or treatment. Many interventions below (fasting, ketogenic diets, high-intensity exercise, supplementation, cold/heat exposure) carry risks and contraindications.
One month, three habits, someone starting from nothing.
Nex-N2.5-Mini (free): 1-Month Beginner Health & Longevity Plan Goal: Build 3 simple habits you can maintain: better food choices, regular movement, and better recovery through sleep/stress management. If you have medical conditions, injuries, or take medications, check with a healthcare professional before starting.
Step 5 Preview: Here is a simple, low-pressure 1-month plan built around three pillars of longevity: Nutrition, Movement, and Sleep & Recovery. The goal is to build tiny habits that stack, not to overhaul your life overnight. Pillar 1: Nutrition (Fuel) Focus: Add good things first; don’t obsess over restriction.
One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.
Nex-N2.5-Mini (free): Experienced software engineer, skeptical of “next word prediction” Think of training an LLM less like teaching it rules and more like running a huge offline simulation. You feed it a corpus of text, tokenize it into chunks, and give it a simple task: given the previous tokens, predict the next token.
Step 5 Preview: 1. The Experienced Software Engineer Think of training an LLM as a massively distributed, automated refactoring job where the compiler is gradient descent. You start with a random function—billions of floating-point parameters—and a loss function that measures how badly it predicts the next token in a sequence.
A collaborative editor that syncs on client clocks. Find what breaks first.
Nex-N2.5-Mini (free): The biggest red flags are: client-clock LWW for document content, polling PostgreSQL for real-time fanout, CDN caching mutable authenticated APIs, per-server WebSocket state with no durable replay, and full HTML snapshots as the main save mechanism.
Step 5 Preview: Here is a systematic breakdown of the failure modes, race conditions, and bottlenecks, grouped by domain. Each includes a concrete remediation and its associated trade-offs.
A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.
Nex-N2.5-Mini (free): The 3 weakest claims are the ones that are broadest, least falsifiable, or mathematically inconsistent. # Weak claim Why it’s weak How to strengthen it 1 “MindMeld AI reads your brainwaves to predict what you want to type before you think it.”
Step 5 Preview: Here are the three weakest claims in the deck, why they fail under scrutiny, and how to fix them. Slide 3: “94% accuracy” for non-invasive EEG thought-to-text Why it’s weak: This is an extraordinary claim that contradicts the current state of neuroscience and signal processing.
Seven pantry ingredients, one dish, and a name worth saying out loud.
Nex-N2.5-Mini (free): Golden Peanut Lantern Noodles Time: Prep 5 min Cook 10 min Serves: 2 Ingredients — 7 pantry staples Spaghetti or any noodles Peanut butter Soy sauce Honey Garlic powder Rice vinegar Water Instructions Cook the noodles: Boil noodles in water until tender. Reserve about ½ cup cooking water, then drain.
Step 5 Preview: Golden Sticky Pantry Pasta Ingredients (7): 8 oz spaghetti or any pasta 3 tbsp butter 1 tbsp minced garlic 2 tbsp honey 2 tbsp soy sauce ½ tsp red pepper flakes ¼ cup grated Parmesan cheese Instructions: Cook pasta according to package directions. Before draining, scoop out ½ cup of pasta water.
Three-star dish, one unusual pairing, plating described in full.
Nex-N2.5-Mini (free): Dish: “Nocturne in Green” — Miso-Cured Turbot, Black Garlic, Green Olive, Oak-Smoked Pear, and Black Carrot Caviar Conceptual narrative: A moonlit orchard beside a cold northern sea.
Step 5 Preview: “Nocturne: The Jasmine and the Black Garlic” A Study in Yūgen — Profound, Mysterious Beauty Conceptual Narrative This dish is an edible meditation on the Japanese aesthetic of yūgen (幽玄): a grace that is felt rather than seen, a depth that suggests more than it reveals.
A consulting contract with traps in it. Find them, then fix them.
Nex-N2.5-Mini (free): Below is a contractor-protective review, not legal advice. Enforceability varies by jurisdiction, especially for non-competes, arbitration, IP assignments, and limitation-of-liability clauses. A local attorney should review before signing.
Step 5 Preview: Disclaimer: This analysis is for educational purposes only and does not constitute legal advice. Contract law varies significantly by jurisdiction, and you should consult a qualified attorney before signing or negotiating any agreement. This agreement is heavily one-sided in the Client’s favor.
Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.
Nex-N2.5-Mini (free): LedgerLift (LLLT) IC Memo — Short Fictional exercise; not investment advice. $mm except per share. Recommendation Recommendation: Short. 12-month PT range: $32–$42 (midpoint ~$37), implying ~17% downside vs. current $46.
Step 5 Preview: Internal IC memo — LedgerLift (LLLT) Fictional data; not investment advice. $ in millions unless noted. Recommendation Short / avoid long. 12-month PT range: $34–$42; thesis-invalidation stop: >$52.
Not enough votes to call it. On the specs, Step 5 Preview has the edge: bigger model tier, bigger context window.
| Spec | ||
|---|---|---|
| Input price | Free | $1/M tokens |
| Output price | Free | $2.7/M tokens |
| Context window | 262K tokens | 1.0M tokens |
| Free API (OpenRouter) | No | No |
| Released | Sep 2026 | Oct 2026 |
| At 10M a month | $0 | $10.00 |
Input tokens at list price. No caching, no batch discount.
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
Nex-N2.5-Mini (free) is developed by Nex AGI while Step 5 Preview is developed by StepFun. Nex-N2.5-Mini (free) has a 262K token context window vs Step 5 Preview's 1.0M. You can compare their actual outputs across 15 challenges on Rival to see how they differ in practice.
It depends on your use case. Nex-N2.5-Mini (free) and Step 5 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 15 challenges so you can judge which fits your needs best.
Nex-N2.5-Mini (free) costs $0/M input tokens and Step 5 Preview costs $1/M input tokens. Nex-N2.5-Mini (free) is $1.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.
This page shows a side-by-side comparison of Nex-N2.5-Mini (free) and Step 5 Preview across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.