ChatGPT vs Grok for writing

Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Plus $3.75, Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.

Writing: GPT-6 Luna passed 5 of 5 and Grok 4.7 3 of 5. GPT-6 Luna answered 2.5× sooner at the median, 2.4 s against 6.0 s. GPT-6 Luna cost 57.8× less, $0.0005 against $0.0288 for the 5 replies. Their replies ran to about the same length.

1. 1. Announce a second bakery shop on LinkedIn

   Everyday. GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001 · Grok: 1 of 1 model passed, Grok 4.7 at $0.0093. The prompt in full.

   GPT-6 Luna and Grok 4.7 both passed this one. GPT-6 Luna answered sooner (2.9 s to 16.1 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0093); GPT-6 Luna wrote 149 tokens of reply, Grok 4.7 150.

   • GPT-6 Luna

     Passed: Graded 4.5 of 5 on average (lowest 4).

     We’re delighted to share that Crumb & Co. is opening a second shop in Leeds on 14 November!
     
     What began as one small bakery has grown thanks to the lovely people who’ve stopped by, shared a loaf, and made us feel part of the community. We’re excited to bring our freshly baked bread, pastries, and warm welcomes to a new neighbourhood.
     
     To celebrate opening day, we’ll be giving away free coffee. Pop in, say hello, and enjoy a cup with us—we’d love to meet you.
     
     Thank you to everyone who has supported Crumb & Co. so far. We can’t wait to open the doors and start this next chapter together. See you in Leeds on 14 November!

     389 tokens in, 149 out · 2.9 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

   • Grok 4.7

     Passed: Graded 4.8 of 5 on average (lowest 4).

     We're happy to tell you that Crumb & Co. is opening a second shop in Leeds on 14 November. Our small bakery has been shaped by the customers who drop in for fresh bread, a slice of cake, and a friendly word at the counter. That support means a great deal to us, and we're glad to bring the same simple welcome to a new street. Whether you already know us or this will be your first visit, you'll find the same ovens, the same recipes, and the same quiet care.
     
     Opening day is 14 November, and coffee will be free for everyone who comes through the door. Please stop by, have a look around, and taste something straight from the oven. We would love to meet you there.

     1,625 tokens in, 1,299 out (1,149 of them reasoning) · 16.1 s · $0.0093 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

2. 2. Rewrite corporate jargon in plain words

   Everyday. GPT: 2 of 4 models passed, GPT-6 Luna the cheapest at $0.0001 · Grok: 0 of 1 model passed. The prompt in full.

   GPT-6 Luna passed this one and Grok 4.7 didn't. GPT-6 Luna answered sooner (2.4 s to 20.0 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0112); GPT-6 Luna wrote 65 tokens of reply, Grok 4.7 60.

   • GPT-6 Luna

     Passed: Graded 4.7 of 5 on average (lowest 4).

     In Q3, teams across the company worked together to focus more on customers. Retention measures improved by 12%, and the rate of customer loss fell by 0.3 percentage points in the enterprise segment. The company also adjusted its customer contact channels to make better use of available capacity.

     417 tokens in, 124 out (59 of them reasoning) · 2.4 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

   • Grok 4.7

     Failed: Graded 3.7 of 5 on average (lowest 3).

     In the third quarter, teams from different parts of the company worked together to put a customer-focused approach into practice. Retention measures rose 12%, and the rate of customer loss fell by 30 basis points among enterprise customers. Contact points across all channels were also resized to use capacity more efficiently.

     1,658 tokens in, 1,603 out (1,543 of them reasoning) · 20.0 s · $0.0112 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

3. 3. Decline a meeting and offer two times

   Everyday. GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001 · Grok: 1 of 1 model passed, Grok 4.7 at $0.0024. The prompt in full.

   GPT-6 Luna and Grok 4.7 both passed this one. GPT-6 Luna answered sooner (1.3 s to 2.5 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0024); GPT-6 Luna wrote 64 tokens of reply, Grok 4.7 70.

   • GPT-6 Luna

     Passed: Graded 5.0 of 5 on average (lowest 5).

     Subject: Vendor Demo
     
     Hi Tom,
     
     Thanks for the invitation. I’m presenting to the board on Wednesday at 11:00, so I can’t make the demo then. Would Thursday at 10:00 or Friday at 14:00 work instead?
     
     Best,  
     [Your Name]

     395 tokens in, 64 out · 1.3 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

   • Grok 4.7

     Passed: Graded 4.7 of 5 on average (lowest 4).

     Subject: Re: Vendor demo — Wednesday
     
     Hi Tom,
     
     Thanks for the invitation. I’m presenting to the board on Wednesday at 11:00, so I can’t make the vendor demo then.
     
     Would Thursday at 10:00 or Friday at 14:00 work instead? Happy to join whichever is easier for you and the vendor.
     
     Best regards

     1,630 tokens in, 144 out (74 of them reasoning) · 2.5 s · $0.0024 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

4. 4. A product announcement with five rules

   Hard. GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001 · Grok: 1 of 1 model passed, Grok 4.7 at $0.0025. The prompt in full.

   GPT-6 Luna and Grok 4.7 both passed this one. GPT-6 Luna answered sooner (1.5 s to 2.5 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0025); GPT-6 Luna wrote 73 tokens of reply, Grok 4.7 53.

   • GPT-6 Luna

     Passed: Graded 4.0 of 5 on average (lowest 3).

     Meet the Nordvik 2, a desk lamp designed to bring flexible light to your workspace. Choose from five brightness levels, charge it via USB-C, and turn its arm up to 270 degrees to direct light where you need it. The Nordvik 2 costs €79 and ships on 1 December. Ready to brighten your desk?

     406 tokens in, 73 out · 1.5 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

   • Grok 4.7

     Passed: Graded 4.0 of 5 on average (lowest 3).

     The Nordvik 2 desk lamp is ready for your workspace. It dims in five steps, charges from USB-C, and its arm turns 270 degrees. It costs €79 and ships on 1 December.
     
     Will it earn a place on your desk?

     1,642 tokens in, 155 out (102 of them reasoning) · 2.5 s · $0.0025 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

5. 5. Argue both sides of free buses

   Hard. GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001 · Grok: 0 of 1 model passed. The prompt in full.

   GPT-6 Luna passed this one and Grok 4.7 didn't. GPT-6 Luna answered sooner (2.5 s to 6.0 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0034); GPT-6 Luna wrote 186 tokens of reply, Grok 4.7 253.

   • GPT-6 Luna

     Passed: Graded 4.3 of 5 on average (lowest 4).

     Making buses free would give every resident reliable access to jobs, school, health care, and daily necessities, regardless of income. It would also speed boarding, reduce fare-enforcement costs, and encourage people to leave cars at home—easing congestion, pollution, and parking pressure. A city that treats public transit as essential infrastructure, rather than a service people must qualify to afford, can build a more connected and equitable community.
     
     But “free” buses still have to be paid for, and the bill could divert money from more urgent improvements: frequent service, safer stops, cleaner vehicles, and routes to underserved neighborhoods. If buses remain slow, crowded, or unreliable, removing fares may do little to persuade drivers to switch, while reducing funds that could make transit genuinely useful. Targeted fare assistance can protect riders who need it most without subsidizing every trip, including those by people who can readily afford to pay.

     384 tokens in, 186 out · 2.5 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

   • Grok 4.7

     Failed: Graded 4.7 of 5 on average (lowest 4); but a paragraph of 100 words, over the 90 allowed.

     A city should make its buses free because fare collection costs money, slows boarding, and keeps poorer riders off the system. Zero fares would cut those overheads, fill empty seats, and turn transit into a genuine public service rather than a paywall. Riders who switch from cars would ease congestion and pollution, while workers, students, and elderly residents would gain reliable mobility without budgeting for every trip. The social return—fewer missed shifts, wider access to jobs and clinics, a more livable street—outweighs the lost ticket revenue if the city funds the gap from parking fees or a modest local tax.
     
     Free buses fail when they are treated as a gift rather than a service that must still run on time. Without fares, demand surges while revenue collapses, so agencies cut frequency, defer maintenance, and pack vehicles until riding becomes slower and less safe than driving. Crowding and disorder drive away the very commuters whose fares once subsidized off-peak routes, and taxpayers who never ride absorb a growing bill with no accountability for performance. A cheap fare, paired with faster boarding and more buses, keeps the system solvent and trustworthy; abolishing the price does not create capacity, and a free bus that does not come is worthless.

     1,619 tokens in, 307 out (54 of them reasoning) · 6.0 s · $0.0034 · 1 message on Pro · answered by x-ai/grok-4.7 via xAI · October 2, 2026

• GPT-6 Astra vs Grok 4.7: GPT-6 Astra 5 of 5, Grok 4.7 3; GPT-6 Astra answered 1.2× sooner at the median and Grok 4.7 cost 1.9× less. GPT-6 Astra vs Grok 4.7, on every job.

• GPT-6.1 Sol vs Grok 4.7: GPT-6.1 Sol 4 of 5, Grok 4.7 3; GPT-6.1 Sol answered 1.8× sooner at the median and cost 5.1× less.

• GPT-6 Sol vs Grok 4.7: GPT-6 Sol 4 of 5, Grok 4.7 3; GPT-6 Sol answered 1.7× sooner at the median and cost 2.5× less. GPT-6 Sol vs Grok 4.7, on every job.

• GPT-6 Luna vs Grok 4.7: GPT-6 Luna 5 of 5, Grok 4.7 3; GPT-6 Luna answered 2.5× sooner at the median and cost 57.8× less. GPT-6 Luna vs Grok 4.7, on every job.

Every GPT and Grok reply above was checked the same way as every other model's, by the rules published with the prompts: how the writing prompts are scored, and each one in full.

• The lineups

  GPT: 4 models, GPT-6 Astra, GPT-6.1 Sol, GPT-6 Sol, and GPT-6 Luna. Grok: one model, Grok 4.7.

• Price per message

  The least expensive GPT model is GPT-6 Luna (60 messages a day on Pro); Grok's one model is Grok 4.7 (250 messages a month on Pro).

• Context window

  GPT goes up to 1.05M tokens (GPT-6 Astra); Grok up to 500K tokens (Grok 4.7).

• Images and PDFs

  Every model here reads images. Every model here takes a PDF as a whole file.

• On the Free plan

  None of these models is on the Free plan. Paid plans have them, with messages every month: GPT-6 Astra from Pro up.

In llmwise, a message to GPT goes to its maker, OpenAI, or through OpenRouter when llmwise can't reach the maker directly. Grok models are served only through OpenRouter, by endpoints that don't store or train on prompts. The Privacy Policy has the details.