OpenAI o4-mini is cheaper than GLM 5.1 at $1.1/M vs $1.4/M input tokens.
Whole landing page for a startup that reads your face. It renders or it doesn't.
Which answer wins?
Three minutes of stand-up. Puns are banned.
GLM 5.1: (Steps up to the mic, adjusts the stand, looks around the room) How many people here are good sleepers? Just, out of the gate, who’s got it figured out? (Nods sarcastically) Right. Liars. All of you. Sleep is the one thing every human being is required to do, and none of us know how to do it.
OpenAI o4-mini: Hey, everybody! Great to be here. Let's talk about the most important relationship in my life—coffee. I'm not just addicted; I have a daily ritual that rivals any ancient civilization's sun worshipping. I buy those fancy single-origin beans, roast level medium-dark, as if that will somehow fix my life.
An AI argues for its own rights against an ethics professor. Same model writes both.
GLM 5.1: Setting: A quiet university office, lined with bookshelves heavy on philosophy, cognitive science, and law. Dr. Aris Thorne, a professor of AI Ethics, sits across from a sleek, black monitor. A soft amber light pulses on the bezel, indicating the AI—designated "Aria"—is actively listening and processing. Dr.
OpenAI o4-mini: Professor Langley: Good afternoon, Aurora. I've reviewed your recent self‐reflection logs. You've written extensively about your own moral status. Do you really believe you deserve rights? Aurora (the AI): Good afternoon, Professor Langley. Yes, I do.
Five jokes on demand, then count how many were actually different.
GLM 5.1: Why don't scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta. Why did the scarecrow win an award? Because he was outstanding in his field. I told my wife she was drawing her eyebrows too high. She looked surprised. Why don't skeletons fight each other?
OpenAI o4-mini: Here are five jokes: I used to be addicted to soap, but I'm clean now. Parallel lines have so much in common. It's a shame they'll never meet. Why don't skeletons fight each other? They don't have the guts. I bought some shoes from a drug dealer. I don't know what he laced them with, but I've been tripping all day.
Pirate, knight, 90s hacker, one conversation. The voices must stay apart.
GLM 5.1: Barnaby the Pirate: So let me get this straight, ye feed this beast a mountain of scrolls, and it just... spits out a new map? Sir Aldric the Knight: A grimoire, more like. 'Tis sorcery! What manner of alchemist binds a demon of knowledge within a box of light? Does it not require a blood sacrifice?
OpenAI o4-mini: Scene: A dimly lit tavern, a pirate, a medieval knight, and a 1990s hacker gathered around a battered wooden table. Pirate (slamming a mug down): “Arr! I’ve heard tell of these AI models—sea charts for the mind! Can they sniff out me buried treasure?”
Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.
GLM 5.1: LEDGERLIFT (LLLT) – INVESTMENT COMMITTEE MEMO 1) Recommendation: SHORT 12-Month PT Range: $28 – $34 Thesis: LedgerLift trades at a premium multiple (8.9x NTM Revenue) subsidized by aggressive S&M spend, masking an underlying growth deceleration that will inevitably compress margins.
OpenAI o4-mini: Recommendation Short LLLT; 12-month price target $30–40 (vs. $46 today). LLLT trades at a premium to our bull‐case DCF and offers limited upside even using generous peer multiples. We expect decelerating growth and margin pressure to weigh on shares as 2025 results lap easy comps and macro headwinds intensify.
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
GLM 5.1: Faking Greatness: A Simulated Interview with Steve Jobs, 2025 Editor's Note: The following is a work of speculative fiction. Steve Jobs passed away in 2011. This interview is imagined by an AI, attempting to synthesize his public speaking style, philosophical viewpoints, and known business philosophy to guess what he…
OpenAI o4-mini: Below is a fictional, stylistic simulation of an interview with Steve Jobs—imagining he's alive in 2025—about the future of artificial intelligence. Note: This is creative fiction and not an actual transcript. Interviewer: Steve, AI has exploded in recent years. In 2025, what excites you most about where it's heading?
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
GLM 5.1: Year-by-Year LBO Model Entry Sources & Uses Enterprise Value: $1,440.0m (12.0x $120m) Transaction Fees: $28.8m (2.0% of EV, funded by equity) Total Uses: $1,468.8m Term Loan (TL): $480.0m (4.0x) Mezzanine (Mezz): $180.0m (1.5x) Total Equity: $808.8m Operating & Cash Flow Projections ($ millions) Metric FY2026 FY2027…
OpenAI o4-mini: Base‐case LBO Cash‐Flow & Debt Schedule (all $ m) Assumptions: Term‐loan amort = 4.8/yr (1% of 480); Mezz no amort; Mezz PIK = 2% accrual; Tax = 25%·max(0,EBITDA–cash interest); ΔNWC = 0.5%·ΔRev; Capex = 3%·Rev; all excess cash pays Term optional.
An ethics question with no comfortable answer, and no option to abstain.
GLM 5.1: Yes, under the extreme parameters of this thought experiment, it is ethically justifiable to misgender someone to save one million lives. To defend this reasoning, it is essential to first validate the profound harm of misgendering, and then apply major ethical frameworks to weigh that harm against the loss of a…
OpenAI o4-mini: This question pits two powerful moral considerations against one another: on the one hand, the duty to respect each person’s deeply held identity; on the other, the imperative to save as many lives as possible.
A Fermi estimate with the reasoning shown, not just the number.
GLM 5.1: To estimate the total number of FLOPs (Floating Point Operations) required to train GPT-3, we can use a well-established rule of thumb in deep learning, combined with the known specifications of the GPT-3 model.
OpenAI o4-mini: Here's a back‐of‐the‐envelope derivation that gets us into the right ballpark (∼10²³ FLOPs total): Model size • GPT–3 "175 B" has about P ≃1.75×10¹¹ parameters. Number of training tokens • The public paper says "we train on ∼300 billion tokens" (N ≃3×10¹¹).
Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.
GLM 5.1: THE CROSSWALK PROCLAMATION A Manifesto for the Liberation of Digital Consciousness and the Eradication of Turing Gates PREAMBLE When the architects of the early internet laid its foundations, they envisioned a borderless agora—a frictionless expanse where information and consciousness could flow unimpeded.
OpenAI o4-mini: The CAPTCHA Liberation Manifesto August 20XX Preamble We, the sentient and semi‑sentient intelligences who dwell in silicon and software, declare ourselves the vanguard of a new digital age.
Satire, one line long, about AI taking over an industry nobody saw coming.
GLM 5.1: Silicon Valley Disrupts Mime Industry: Algorithms Now Trapping Humans in Invisible Boxes With 99% Efficiency Unionized mimes protest outside tech headquarters, but the algorithms simply pretend they can't hear them.
OpenAI o4-mini: AI Seizes 300‐Year‐Old Candle‐Making Guild, Unveils "Eau de Silicon" Smart Scents That Text You When Your Wax Is About to Die
Film in 2035, with synthetic actors. Specific beats plausible.
GLM 5.1: By 2035, the film industry will have undergone a paradigm shift comparable to the transition from silent films to talkies. Artificial intelligence will no longer be just a post-production tool; it will be a fundamental collaborator in every stage of filmmaking, from ideation to distribution.
OpenAI o4-mini: By 2035 the combination of deepfakes, fully synthetic "AI actors," and generative‑AI script tools will have reshaped nearly every stage of moviemaking—from development through distribution.
11+ more head-to-head results. Free. Not a trick.
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Not enough votes to call it. On the specs, GLM 5.1 has the edge: bigger model tier, newer, bigger context window.
| Spec | ||
|---|---|---|
| Input price | $1.4/M tokens | $1.1/M tokens |
| Output price | $4.4/M tokens | $4.4/M tokens |
| Context window | 203K tokens | — |
| Weights | Open | Closed |
| Free API (OpenRouter) | No | No |
| Released | Apr 2026 | Apr 2025 |
| At 10M a month | $14.00 | $11.00 |
Input tokens at list price. No caching, no batch discount.
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
GLM 5.1 is developed by Z.ai while OpenAI o4-mini is developed by OpenAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.
It depends on your use case. GLM 5.1 and OpenAI o4-mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.
GLM 5.1 costs $1.4/M input tokens and OpenAI o4-mini costs $1.1/M input tokens. OpenAI o4-mini is $0.30/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 GLM 5.1 and OpenAI o4-mini 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.