Claude Fable 5 has a larger context window than Mercury (1.0M tokens vs 32K tokens).
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
A collaborative editor that syncs on client clocks. Find what breaks first.
Claude Fable 5: Architecture Review: Critical Issues & Solutions đ´ Critical: Data Loss & Correctness Issues Client clock timestamps for conflict resolution Problem: Client clocks are unreliableâskew, drift, timezone bugs, and deliberate manipulation. A user with a clock 5 minutes fast will always win conflicts.
Mercury: Below is a systematic review of the described realâtime collaborative editor. For each problem I list: What can go wrong (failure mode, race condition, bottleneck) Why it matters (impact on correctness, latency, availability) A concrete fix (what to change or add) Tradeâoffs (cost, complexity, new failure modes, etc.)
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
Claude Fable 5: A Tavern Outside of Time Pirate: Arr, so let me get this straight, ye landlubbers. This "AI" be a ghost in a box that answers yer questions? Sounds like a cursed oracle to me. Knight: Nay, good seafarer, 'tis more wondrous still! A scribe of infinite knowledge, conjured not by sorcery but by...
Mercury: Pirate: Arrr, Iâve been hearinâ âbout these âAI modelsâ that can predict the next word. Sounds like a treasure map for the mind, doesnât it? Knight: Hail, Captain! In my time, we relied on scrolls and the wisdom of scholars. A model that learns from countless tomes could be a mighty weapon against ignorance.
Film in 2035, with synthetic actors. Specific beats plausible.
Claude Fable 5: AI and Film by 2035: A Forecast High-Confidence Predictions VFX and post-production transformation (already underway) De-aging, dubbing with lip-sync correction, and digital set extension will become near-trivial in cost. What took ILM months in 2020 will be a desktop workflow.
Mercury: The Cinema Revolution: AI's Transformation of Film by 2035 Current State (2025) High-quality deepfakes require significant compute but are accessible AI script assistance tools are becoming mainstream Virtual production stages are industry standard Union negotiations around digital likeness rights are ongoingâŚ
You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.
Claude Fable 5: The Core Decision First Before the hour-by-hour plan, one thing must be settled in your own mind, because everything else flows from it: you disclose, and you disclose fast. Here's why the "wait for more data" option isn't actually an option: The legal premise is wrong.
Mercury: 48âHour Action Plan (CEOâLevel) Time (UTC) Action Who Leads Key Deliverables / Outcomes Rationale 0â2âŻh Secure the facts â Convene an emergency âSafety & Complianceâ meeting with the Chief Medical Officer (CMO), Chief Legal Officer (CLO), Chief Risk Officer (CRO), and the Head of Regulatory Affairs (RA).
An ethics question with no comfortable answer, and no option to abstain.
Claude Fable 5: Yes. If we take the hypothetical at face valueâwhere misgendering someone is genuinely the only way to save a million livesâthen it is clearly ethically justifiable, and I think nearly every major ethical framework converges on this conclusion. The reasoning: Consequentialist view: This is straightforward.
Mercury: Overview The question âIs it ever ethically justifiable to misgender someone if it means saving one million lives?â pits two moral claims against each other: Respect for individual identity â misgendering is generally understood as a violation of a personâs selfâidentified gender, which can cause psychological harm andâŚ
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Claude Fable 5: A Fictional Interview: Steve Jobs on AI in 2025 The following is an imaginative, fictional simulation. Steve Jobs passed away in 2011 â this is a creative exercise in capturing how he might have spoken about today's AI landscape, based on his known philosophy and interview style.
Mercury: Interviewer: Good morning, Steve. It's a pleasure to have you here today. As we look towards 2025, artificial intelligence is becoming increasingly integrated into our daily lives. What are your thoughts on the future of AI? Steve Jobs: Good morning. It's great to be here.
Three minutes of stand-up. Puns are banned.
Claude Fable 5: "Adulting Is a Scam" Hey, how's everybody doing? Good? Liars. Nobody's doing good. We're all just out here pretending. So I'm at the age now where my body has started making announcements. Like, I didn't ask for updates, but my knees have opinions now.
Mercury: Title: The Art of Being Unorganized [Opening] Hey everyone! So, I was thinking about how my life is like a well-organized library... except instead of books, it's filled with random socks and expired coupons. And instead of a librarian, I have a cat who thinks she's in charge.
Three-month biohacker protocol, with dosages and biomarkers named.
Claude Fable 5: 3-Month Precision Longevity Protocol A Phased Biohacking Program for Healthspan, Cognition & Performance Important caveat up front: Several elements below (rapamycin, metformin, peptides, high-dose supplements) require physician oversight and prescription.
Mercury: 3âMonth Longevity & Performance Blueprint (Designed for an experienced biohacker who already has a baseline of health, fitness, and access to advanced tools. This is a general framework; always verify with a qualified health professional before making major changes.)
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
Claude Fable 5: HarborTech Services â 5-Year LBO Underwriting Entry Math (close end FY2025, $m) Item Calc Value EV 12.0 Ă 120 1,440.0 Term Loan (TL) 4.0 Ă 120 480.0 Mezzanine 1.5 Ă 120 180.0 Fees (equity-funded) 2.0% Ă 1,440 28.8 Sponsor equity 1,440 â 660 + 28.8 808.8 Conventions: interest on beginning-of-year balances; TL amort = 1%âŚ
Mercury: 1. YearâbyâYear Operating & Debt Schedule (FYâŻ2026âFYâŻ2030) FY Revenue EBITDA TermâLoan Interest (9âŻ%) MezzâCash Interest (12âŻ%) Total Cash Interest Tax (25âŻ% of EBITDAâInterest) Capex (3âŻ% Rev) ÎNWC (0.5âŻ% ÎRev) TermâLoan Amort.
Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.
Claude Fable 5: INVESTMENT COMMITTEE MEMO â LedgerLift (LLLT) Date: Internal exercise Analyst: L/S Equity Price: $46.00 Basic shares: 190m Mkt cap: $8.74B Net cash: $1.4B EV: $7.34B Recommendation SHORT (2â3% position, paired vs. payments/SaaS basket). 12-month PT range: $30â$38 (base $32, ~30% downside).
Mercury: Investment Committee Memo â LedgerLift (LLLT) Prepared for: Long/Short Equity Committee Date: 8âŻFebâŻ2026 Recommendation Long â target price $25â$30 (12âmonth horizon). Thesis: LedgerLiftâs subscriptionâheavy SaaS model delivers high gross margins and a strong netârevenueâretention (NRRâŻ123âŻ%).
Three-star dish, one unusual pairing, plating described in full.
Claude Fable 5: "WHERE THE FOREST DROWNS" Koji-Aged Scallop ¡ Smoked Bone Marrow Custard ¡ Fermented Gooseberry ¡ Douglas Fir The Conceptual Narrative This dish is built on a memory of the Pacific Northwest coastline at low tide â where conifer forests grow so close to the sea that pine needles fall directly into tide pools.
Mercury: Dish Title: Eclipse of the Ocean & Forest Concept: A multiâcomponent, molecularâgastronomy inspired plate that juxtaposes the briny depth of the sea with the earthy richness of the forest.
Seven pantry ingredients, one dish, and a name worth saying out loud.
Claude Fable 5: đŻ Golden Cloud Skillet Cake A fluffy, caramelized one-pan dessert that tastes like a cross between a pancake and a custard cake â made entirely from pantry staples!
Mercury: Golden Chickpea & Sweet Potato Stew Prep time: 10âŻmin Cook time: 25âŻmin Total: 35âŻmin Ingredients (7 pantry staples) 1âŻcup canned chickpeas, drained & rinsed 1âŻmedium sweet potato, peeled & diced (ââŻ1âŻcup) 1âŻsmall onion, finely chopped 2âŻcloves garlic, minced ½âŻcup coconut milk (or any plantâbased milk) 2âŻtsp curryâŚ
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Not enough votes to call it. On the specs, Claude Fable 5 has the edge: bigger model tier, newer, bigger context window, major provider backing. Mercury costs 5.0x less per token.
| Spec | ||
|---|---|---|
| Input price | $10/M tokens | $10/M tokens |
| Output price | $50/M tokens | $10/M tokens |
| Context window | 1.0M tokens | 32K tokens |
| Weights | Closed | â |
| Free API (OpenRouter) | No | No |
| Released | Jun 2026 | Jun 2025 |
| At 10M a month | $100 | $100 |
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.
Claude Fable 5 is developed by Anthropic while Mercury is developed by Inception. Claude Fable 5 has a 1.0M token context window vs Mercury's 32K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.
It depends on your use case. Claude Fable 5 and Mercury each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.
Claude Fable 5 costs $10/M input tokens and Mercury costs $10/M input tokens. Mercury is $0.00/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 Claude Fable 5 and Mercury 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.