The short answer
The best AI for copywriting in 2026 is Anthropic's Claude, because it follows detailed briefs, keeps a brand voice through Projects and critiques weak lines honestly; Claude Opus 5.5 runs on Pro and above. The runner-up is Grammarly Pro, which keeps a team's copy on one style guide and brand tone. The best free option is OpenAI's ChatGPT Free, with unlimited text chats on GPT-6 Luna within OpenAI's guardrails.
| Our pick | Claude (Opus 5.5 on Pro and up; Sonnet 5.5 on Free) |
|---|---|
| Runner-up | Grammarly Pro (style guide, brand tone, 2,000 AI prompts per member a month) |
| Best free | ChatGPT Free (GPT-6 Luna, unlimited text chats within guardrails) |
| For visuals | Canva or ChatGPT; Claude does not make images |
| Always check | Every number, quote and product claim |
| Privacy | Turn off training on personal plans before pasting client work |
The best AI for copywriting in 2026, in short
Copywriting is the hardest writing job to hand to AI, because the whole point is to sound like a specific brand talking to a specific person, and AI's default voice is the average of everything it has read. The tool that wins is the one that follows a detailed brief closely, keeps your voice across a long session and tells you honestly which line is weak. On that test, Anthropic's Claude is our pick. The runner-up is Grammarly Pro, for a different reason: it keeps a whole team's copy on one style guide and brand tone in the apps where people already write. The best free option is OpenAI's ChatGPT on its free plan, which gives unlimited text chats with GPT-6 Luna, within OpenAI's abuse guardrails.
| Our pick: Claude | Runner-up: Grammarly Pro | Best free: ChatGPT Free | |
|---|---|---|---|
| Best for | Drafting and critiquing copy from a brief | Keeping a team's copy on brand everywhere | High-volume variants at no cost |
| Models | Claude Opus 5.5 on Pro and up; Sonnet 5.5 and Haiku 5.5 on Free | Not named by Grammarly | GPT-6 Luna on Free; GPT-6 Sol on Plus |
| Keeps your voice | Projects (up to 5 on Free, unlimited on Pro) and memory | Style guide, brand tone and snippets | Memory, limited on Free |
| Images | No: Claude does not generate photos or illustrations | No | Yes, limited on Free |
| Trains on your text | Free to Ultra: yes unless you opt out | On by default for Free, Premium and web-bought Pro | Yes unless you opt out |
Our pick: Claude
Why. Claude is Anthropic's AI assistant, and careful writing and editing is what it is best known for. In copywriting that shows in three ways. It follows a long brief without drifting back to generic marketing language. It is willing to say a line is weak and explain why, which is the feedback you actually need. And it keeps a voice across a session, so the tenth email in a sequence still sounds like the first. Put your brand guidelines, three pieces of copy you love and your product facts in a Claude Project, and every chat in that Project starts from them. Claude Opus 5.5, released on 22 September 2026, is the model to use on Pro and above; the free plan runs on Claude Sonnet 5.5 and Claude Haiku 5.5, which are good enough for most short copy.
Who it suits. Copywriters, content marketers and founders who write their own landing pages, emails and ads, and anyone who wants a sparring partner that critiques rather than flatters. It also suits long-form copy such as sales pages and case studies, where keeping the argument coherent over many sections matters.
The catch. Usage limits apply on every plan, and long sessions with Opus use your allowance faster. Claude does not make images, so visuals for ads and social posts need another tool such as Canva or ChatGPT. And on Free, Pro, Max and Ultra your chats can be used to train Anthropic's models unless you turn off Help Improve our AI models under Settings, then Privacy. Do that before you paste a client's unreleased product details. More in our Claude guide.
Runner-up: Grammarly Pro for teams that need one voice
Why. Grammarly, now one of the products in the Superhuman suite after the company renamed itself Superhuman, does something no chat assistant does: it checks copy where it is written, in Google Docs, Microsoft Office, your browser and email, against your rules. Grammarly Pro adds full-sentence rewrites, tone adjustment, a team style guide, a brand tone, snippets and team analytics, with 2,000 AI prompts per member a month. It also includes plagiarism and AI-text detection, which helps when you hand copy to a client. For a marketing team where five people write product copy, that consistency is worth more than a slightly better first draft.
Who it suits. In-house marketing and content teams, agencies with several writers on one account, and non-native English speakers who write professional copy every day.
The catch. Grammarly is an editor, not a strategist. It will not work out your positioning or write a strong long-form page from a blank brief as well as a general assistant. Product Improvement and Training is on by default for Free, Premium, single-user Pro and multi-user Pro bought on the website, so switch it off at account.grammarly.com/security/privacy on Free or Premium, or at account.grammarly.com/admin/data_settings on Pro, where on a multi-user account only an admin can. Compare the two directly in Grammarly vs Claude, or see Grammarly alternatives.
Best free option: ChatGPT Free
Why. For generating lots of variants quickly, ChatGPT's free plan is hard to beat: OpenAI lists unlimited text chats with GPT-6 Luna, within abuse guardrails, plus limited image creation, uploads and deep research. That is enough to produce twenty headline options, test three angles for an ad or rewrite a product description for different audiences without hitting a wall. Since October 2026 ChatGPT can also lay out answers as side-by-side comparisons, which is handy when you are choosing between versions.
Who it suits. Freelancers and small businesses starting out, and anyone who needs volume more than polish, such as ad variants and subject lines for testing.
The catch. The free plan uses GPT-6 Luna, OpenAI's smaller model, and a short GPT Instant context window of about 12 pages of input, so a long brand guide plus a long draft may not fit. Plus, Pro, Business and Enterprise get GPT-6 Sol; Go stays on GPT-6 Luna. On personal Free, Go, Plus and Pro accounts chats can train OpenAI's models unless you turn off Improve the model for everyone under Settings, then Data controls. If you ask for a table to paste into a deck, say so, or you may get an interactive widget instead. See our ChatGPT guide and ChatGPT vs Claude.
How to choose: three questions
- Do you need a writer or an editor? If you want first drafts and critique from a brief, pick a general assistant (Claude, or ChatGPT on a budget). If your team already writes and needs consistency, pick Grammarly Pro.
- How much brand material does the tool need to hold? A one-page voice guide fits anywhere. A full brand book, a product spec and past campaigns need Projects in Claude or ChatGPT Plus or Pro with a bigger context window.
- Whose words are you pasting in? Client copy and unreleased product details belong in a work plan that does not train on your content by default (Claude Team or Enterprise, ChatGPT Business or Enterprise, Grammarly bought through sales) or in a personal account with training switched off.
A copywriting workflow with AI, from brief to final line
Here is how a landing page for a new product goes from brief to finished copy. The same steps work for an email sequence or a set of ads.
- Write a real brief first. Audience, the one problem they have, the one action you want, three proof points, the objections you hear most and words the brand never uses. Ten minutes here saves an hour of fixing generic drafts.
- Teach the voice. Paste three pieces of copy that sound right and ask the assistant to describe the voice as rules. Correct the rules, then save them in a Claude Project (or a ChatGPT project on Plus or above) so you never paste them again.
- Ask for angles before copy. Get five different angles for the headline and opening (the cost of doing nothing, the quick win, the proof, the contrarian view, the customer's own words). Pick one. This is where your judgement matters most.
- Draft section by section. Ask for the hero, then the problem, then the proof, rather than the whole page at once. Short asks keep quality high.
- Make it critique itself. Ask the assistant to read the draft as a sceptical customer and list the three lines it would not believe. Fix those lines with real numbers or cut them.
- Check every claim. AI invents plausible statistics, customer quotes and feature details. Every number, quote and promise must trace back to something true. This is also a legal question in advertising, not just a quality one.
- Polish where it is published. Run the final copy through Grammarly or your team's style check in the document where it will live, then read it aloud.
What AI copy still gets wrong
Three habits give AI copy away. It opens with a broad statement about the reader's world instead of a specific problem. It stacks three adjectives where one concrete fact would do. And it ends every section with a tidy summary line. Ban all three in your brief, and ask for a number, a name or an example in every paragraph. The second problem is sameness: if your competitors use the same tools with lazy prompts, everyone's homepage starts to sound alike. Your advantage is the input only you have, such as customer interviews, support tickets and sales call notes. Feed those in and the copy stops sounding like everyone else's. For campaign-level help, see the best AI for marketing and our guide for marketers.
Copywriting prompts to copy
These eight prompts work in Claude, ChatGPT or any capable assistant. Replace everything in [square brackets]. Prompt 2 is the one to run first on any new project.
Prompts to copy
Turn a brief into five angles
Here is my brief: audience [who], problem [what], action [what you want them to do], proof [three facts], objections [list]. Give me five distinct angles for a [landing page / ad / email], each with a headline under 10 words, a one-sentence opening and a note on who it will work best for. Do not write the full copy yet.
You get: Five real choices of direction before any drafting
Extract our brand voice as rules
Here are three pieces of copy that sound like our brand: [paste]. Describe the voice as 8 to 10 rules covering sentence length, vocabulary, humour, how we address the reader and words we never use. Quote a line from the samples for each rule. I will correct the rules and reuse them.
You get: A voice guide you can save and reuse in every project
Headline variants with reasons
Write 15 headlines for [product] aimed at [audience], in five groups of three: benefit, curiosity, proof, urgency and the customer's own words. Keep each under [number] characters. Then pick your best three and explain in one line each why it would work for this audience.
You get: Fifteen options grouped by approach, with a shortlist
Read my copy as a sceptical customer
Read this copy as a sceptical [job title] who has been burned by similar products before: [paste copy]. List the five lines you would not believe or would skip, say why for each, and suggest what proof or rewrite would win you over. Be blunt.
You get: The weak lines and how to fix them, before customers find them
Product description for three audiences
Here are the facts about [product]: [paste specs and benefits]. Write a 60-word product description for each of these audiences: [audience 1], [audience 2], [audience 3]. Use only the facts given. If a benefit needs a fact I did not provide, mark it [CHECK] instead of inventing it.
You get: Three tailored descriptions with no invented claims
Ad copy within character limits
Write [5] ad variations for [platform] promoting [offer] to [audience]. Each needs a headline of at most [number] characters, a primary text of at most [number] characters and a call to action. Show the character count after each line. Vary the angle in each one.
You get: Ad variants that fit the platform, ready for a test
Answer the top objections
Our customers hesitate for these reasons: [list objections]. For each, write a short answer for the FAQ section of our sales page (under 50 words), in our voice: [paste voice rules]. Use only these facts: [paste facts]. End with a list of objections you think we are missing.
You get: Objection-handling copy and a list of gaps
Cut it to the bone
Edit this copy to [60%] of its length: [paste]. Keep every claim, number and call to action. Remove filler, repeated ideas and adjectives that do not add meaning. Show the new version, then a list of what you cut so I can put anything important back.
You get: Tighter copy and a record of every cut