Claude vs DeepSeek 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: Claude Sonnet 5 passed 4 of 5 and DeepSeek V4 Pro 5 of 5. DeepSeek V4 Pro answered 1.1× sooner at the median, 4.5 s against 3.9 s. DeepSeek V4 Pro cost 3.2× less, $0.0171 against $0.0054 for the 5 replies. Claude Sonnet 5's replies ran 119% longer, in tokens of reply, thinking not counted.

1. 1. Announce a second bakery shop on LinkedIn

   Everyday. Claude: 5 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0002 · DeepSeek: 2 of 2 models passed, DeepSeek V4.1 Flash the cheapest at $0.0004. The prompt in full.

   DeepSeek V4 Pro passed this one and Claude Sonnet 5 didn't. DeepSeek V4 Pro answered sooner (3.9 s to 4.6 s), and DeepSeek V4 Pro's reply cost less ($0.0010 to $0.0037); Claude Sonnet 5 wrote 267 tokens of reply, DeepSeek V4 Pro 164.

   • Claude Sonnet 5

     Failed: Graded 3.5 of 5 on average (lowest 3).

     We have some exciting news to share: Crumb & Co. is opening our second shop, this time in Leeds!
     
     From our very first bakery, we've believed in doing simple things well — proper sourdough, honest pastries, and coffee worth stopping for. Now we get to bring that same spirit to a new neighbourhood and, hopefully, a whole new group of familiar faces.
     
     Our Leeds shop opens its doors on 14 November, and we'd love for you to be there. To celebrate, every coffee on opening day is on us — no catch, just our way of saying thank you for supporting us along the way.
     
     This has been months of planning, a lot of taste-testing, and more excitement than we know what to do with. We can't wait to welcome you in, share some fresh bakes, and start building new memories together.
     
     See you there — first coffee's on the house.

     538 tokens in, 267 out · 4.6 s · $0.0037 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

   • DeepSeek V4 Pro

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

     Big news from Crumb & Co. — we're opening a second shop, and this time we're heading to Leeds.
     
     Our new bakery will open its doors on Thursday 14 November, and we'd love you to be among the first through them. Come and see the new space, smell the bread coming out of the oven, and say hello to the team.
     
     To mark the day, we're giving away free coffee to everyone who visits — our way of saying thank you for supporting a small, independent bakery.
     
     We've spent months getting this little shop ready, and we're equal parts nervous and excited. If you're in Leeds, we'd be glad to see you. Bring a friend, grab a warm loaf, and help us make it feel like home.
     
     See you on the 14th.

     400 tokens in, 199 out (35 of them reasoning) · 3.9 s · $0.0010 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 7, 2026

2. 2. Rewrite corporate jargon in plain words

   Everyday. Claude: 5 of 6 models passed, Claude Haiku 4.5 the cheapest at $0.0008 · DeepSeek: 1 of 2 models passed, DeepSeek V4 Pro at $0.0024. The prompt in full.

   Claude Sonnet 5 and DeepSeek V4 Pro both passed this one. Claude Sonnet 5 answered sooner (2.7 s to 5.8 s), and cost about the same; Claude Sonnet 5 wrote 105 tokens of reply, DeepSeek V4 Pro 58.

   • Claude Sonnet 5

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

     In Q3, teams worked together to focus more on customers' needs. This effort increased customer retention by 12% and reduced the rate of customer loss (churn) by 0.3 percentage points among large business clients. The company also adjusted the number of customer contact channels (like phone, email, and chat) to better manage workload and resources.

     597 tokens in, 105 out · 2.7 s · $0.0022 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

   • DeepSeek V4 Pro

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

     In the third quarter, our teams worked together to focus more on customers. This produced a 12% increase in customer retention and a 0.30 percentage point drop in churn among business customers. We also fine-tuned our various customer contact channels to use resources more efficiently.

     431 tokens in, 576 out (518 of them reasoning) · 5.8 s · $0.0024 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 7, 2026

3. 3. Decline a meeting and offer two times

   Everyday. Claude: 6 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0001 · DeepSeek: 2 of 2 models passed, DeepSeek V4.1 Flash the cheapest at $0.0002. The prompt in full.

   Claude Sonnet 5 and DeepSeek V4 Pro both passed this one. Claude Sonnet 5 answered sooner (2.8 s to 3.3 s), and DeepSeek V4 Pro's reply cost less ($0.0006 to $0.0026); Claude Sonnet 5 wrote 149 tokens of reply, DeepSeek V4 Pro 82.

   • Claude Sonnet 5

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

     Subject: Re: Vendor Demo – Wednesday 11:00
     
     Hi Tom,
     
     Thanks for the invite! Unfortunately, I have a board presentation at that time on Wednesday, so I won't be able to join.
     
     Would Thursday at 10:00 or Friday at 14:00 work instead? Happy to make either one work on my end.
     
     Let me know what suits you, and I'll get it on the calendar.
     
     Best,
     [Your Name]

     542 tokens in, 149 out · 2.8 s · $0.0026 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

   • DeepSeek V4 Pro

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

     Subject: Vendor demo – alternative times
     
     Hi Tom,
     
     Thanks for the invitation to the vendor demo on Wednesday at 11:00. Unfortunately, I’m presenting to the board at that time, so I won’t be able to join.
     
     Would Thursday at 10:00 or Friday at 14:00 work for you instead? I’m happy to make either time work.
     
     Best regards

     406 tokens in, 120 out (38 of them reasoning) · 3.3 s · $0.0006 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 8, 2026

4. 4. A product announcement with five rules

   Hard. Claude: 4 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0001 · DeepSeek: 2 of 2 models passed, DeepSeek V4.1 Flash the cheapest at $0.0003. The prompt in full.

   Claude Sonnet 5 and DeepSeek V4 Pro both passed this one. DeepSeek V4 Pro answered sooner (1.8 s to 4.5 s), and DeepSeek V4 Pro's reply cost less ($0.0005 to $0.0035); Claude Sonnet 5 wrote 235 tokens of reply, DeepSeek V4 Pro 71.

   • Claude Sonnet 5

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

     **Introducing the Nordvik 2 Desk Lamp**
     
     Meet the Nordvik 2, thoughtfully redesigned for how you actually work. Five-step dimming lets you fine-tune brightness for any task, from focused reading to ambient evening light. The 270-degree rotating arm adjusts to virtually any angle, giving you precise control over where light falls. USB-C charging means one cable does it all, keeping your desk clutter-free and compatible with everything else you own.
     
     Priced at €79, the Nordvik 2 brings premium design and functionality within easy reach. It begins shipping on 1 December, just in time to brighten your winter workspace.
     
     Ready to see how the right light changes the way you work?

     554 tokens in, 235 out · 4.5 s · $0.0035 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

   • DeepSeek V4 Pro

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

     Introducing the Nordvik 2 desk lamp. It dims in five steps, so you can find the right light for any task. It charges over USB-C, keeping your desk free of extra cables. The arm turns 270 degrees for precise positioning. Available for €79, with shipping on 1 December. Have you reserved yours yet?

     418 tokens in, 96 out (25 of them reasoning) · 1.8 s · $0.0005 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 8, 2026

5. 5. Argue both sides of free buses

   Hard. Claude: 2 of 6 models passed, Claude Haiku 4.5 the cheapest at $0.0014 · DeepSeek: 2 of 2 models passed, DeepSeek V4 Pro the cheapest at $0.0009. The prompt in full.

   Claude Sonnet 5 and DeepSeek V4 Pro both passed this one. DeepSeek V4 Pro answered sooner (4.1 s to 6.6 s), and DeepSeek V4 Pro's reply cost less ($0.0009 to $0.0050); Claude Sonnet 5 wrote 401 tokens of reply, DeepSeek V4 Pro 153.

   • Claude Sonnet 5

     Passed: Graded 4.0 of 5 on average (lowest 4).

     Free buses would boost ridership, cut traffic congestion, and reduce emissions by encouraging drivers to switch to transit. Lower-income residents, who rely most heavily on public transportation, would benefit enormously from eliminated fare burdens, improving access to jobs, education, and healthcare. Free transit also simplifies operations, speeding boarding times and eliminating costly fare collection infrastructure. Cities that have tried this, like Kansas City, saw ridership increases and stronger community mobility, suggesting free buses are both an equity tool and a practical urban planning solution.
     
     However, fares provide crucial revenue that funds maintenance, expansion, and service reliability. Eliminating them shifts costs entirely onto taxpayers, straining budgets already stretched thin, potentially forcing service cuts elsewhere. Free buses often attract overcrowding without corresponding investment in more vehicles, degrading service quality for existing riders. Critics also note that the poorest riders may already receive subsidized passes, making universal free fares a regressive policy that primarily benefits wealthier occasional riders. Better targeted subsidies, they argue, would achieve equity goals more efficiently than blanket free fares citywide.

     518 tokens in, 401 out · 6.6 s · $0.0050 · 1 message on Pro · answered by anthropic/claude-sonnet-5 via Claude Platform on AWS · September 27, 2026

   • DeepSeek V4 Pro

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

     Making buses free turns public transit into a true public good, like sidewalks or libraries. It removes fares as a barrier for low-income riders, boosts ridership, cuts traffic congestion and emissions, and speeds boarding by eliminating payment delays. Cities already subsidize most transit costs; dropping the small fare share is a modest investment with outsized returns in mobility, equity, and cleaner air.
     
     The strongest case against free buses is that fares, however small, are the only direct signal of demand. Removing them invites overcrowding on popular routes while doing nothing to expand service where it is sparse. Scarce transit dollars are better spent on frequency, reliability, and coverage—improvements that actually attract riders—than on subsidizing trips for people who can already afford to pay.

     395 tokens in, 193 out (40 of them reasoning) · 4.1 s · $0.0009 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer · October 8, 2026

• Claude Fable 5.1 vs DeepSeek V4 Pro: Claude Fable 5.1 3 of 5, DeepSeek V4 Pro 5; DeepSeek V4 Pro answered 1.5× sooner at the median and cost 16.1× less.

• Claude Fable 5.1 vs DeepSeek V4.1 Flash: Claude Fable 5.1 3 of 5, DeepSeek V4.1 Flash 4; DeepSeek V4.1 Flash answered 4.5× sooner at the median and cost 38.3× less.

• Claude Opus 5.5 vs DeepSeek V4 Pro: Claude Opus 5.5 4 of 5, DeepSeek V4 Pro 5; DeepSeek V4 Pro answered 2.1× sooner at the median and cost 17.2× less. Claude Opus 5.5 vs DeepSeek V4 Pro, on every job.

• Claude Opus 5.5 vs DeepSeek V4.1 Flash: 4 of 5 each; DeepSeek V4.1 Flash answered 6.2× sooner at the median and cost 41.0× less.

• Claude Sonnet 5.5 vs DeepSeek V4 Pro: Claude Sonnet 5.5 4 of 5, DeepSeek V4 Pro 5; Claude Sonnet 5.5 answered 1.7× sooner at the median and DeepSeek V4 Pro cost 3.2× less.

• Claude Sonnet 5.5 vs DeepSeek V4.1 Flash: 4 of 5 each; DeepSeek V4.1 Flash answered 1.8× sooner at the median and cost 7.6× less.

• Claude Sonnet 5 vs DeepSeek V4 Pro: Claude Sonnet 5 4 of 5, DeepSeek V4 Pro 5; DeepSeek V4 Pro answered 1.1× sooner at the median and cost 3.2× less. Claude Sonnet 5 vs DeepSeek V4 Pro, on every job.

• Claude Sonnet 5 vs DeepSeek V4.1 Flash: 4 of 5 each; DeepSeek V4.1 Flash answered 3.3× sooner at the median and cost 7.6× less.

• Claude Haiku 4.5 vs DeepSeek V4 Pro: Claude Haiku 4.5 4 of 5, DeepSeek V4 Pro 5; Claude Haiku 4.5 answered 1.8× sooner at the median and cost about the same. Claude Haiku 4.5 vs DeepSeek V4 Pro, on every job.

• Claude Haiku 4.5 vs DeepSeek V4.1 Flash: 4 of 5 each; DeepSeek V4.1 Flash answered 1.7× sooner at the median and cost 2.5× less. Claude Haiku 4.5 vs DeepSeek V4.1 Flash, on every job.

• Claude Haiku 5.5 vs DeepSeek V4 Pro: Claude Haiku 5.5 3 of 5, DeepSeek V4 Pro 5; Claude Haiku 5.5 answered 2.6× sooner at the median and cost 6.7× less.

• Claude Haiku 5.5 vs DeepSeek V4.1 Flash: Claude Haiku 5.5 3 of 5, DeepSeek V4.1 Flash 4; DeepSeek V4.1 Flash answered 1.1× sooner at the median and Claude Haiku 5.5 cost 2.8× less. Claude Haiku 5.5 vs DeepSeek V4.1 Flash, on every job.

Every Claude and DeepSeek 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

  Claude: 6 models, Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 4.5, and Claude Haiku 5.5. DeepSeek: 2 models, DeepSeek V4 Pro and DeepSeek V4.1 Flash.

• Price per message

  The least expensive Claude model is Claude Haiku 5.5 (60 messages a day on Pro); the least expensive DeepSeek model is DeepSeek V4.1 Flash (60 messages a day on Pro).

• Context window

  Claude goes up to 1M tokens (Claude Fable 5.1); DeepSeek up to 1.05M tokens (DeepSeek V4 Pro).

• Images and PDFs

  DeepSeek V4 Pro doesn't read images. DeepSeek V4 Pro and DeepSeek V4.1 Flash get a PDF's text rather than the file itself.

• On the Free plan

  Free's one-time trial of 5 messages covers Claude Haiku 5.5. Paid plans have them, with messages every month: Claude Fable 5.1 from Pro up.

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