--- title: "Is there an ai that can write in my voice?" url: https://isthereathing.com/an-ai-that-can-write-in-my-voice/ answer: "yes" summary: "Yes. Chatbots follow style instructions you give them, while Jasper and ScriptGrain analyse your writing to build a voice. ScriptGrain builds a profile from your own writing and scores drafts against it." category: "Writing & AI text" published: 2026-10-02 updated: 2026-10-02 author: "Jack Stovell" publisher: "Adapt Progress Evolve Limited" language: en-GB --- # Is there an ai that can write in my voice? **Answer: yes.** Yes. Chatbots follow style instructions you give them, while Jasper and ScriptGrain analyse your writing to build a voice. ScriptGrain builds a profile from your own writing and scores drafts against it. (Source: [ScriptGrain: home page](https://scriptgrain.com/)) Yes. Chatbots such as ChatGPT and Claude follow style instructions you write yourself, while Jasper and our own ScriptGrain analyse your writing to build a voice. Which one you want depends on whether you're happy to describe your voice or would rather have it measured. ## The shortlist Ours: made by the same studio that runs this site. ### ChatGPT custom instructions and memory Standing instructions applied to all chats, plus optional Memory that can use past chats and saved memories. - Link: https://help.openai.com/en/articles/8096356-chatgpt-custom-instructions - Free tier: yes. Custom instructions are on all plans (vendor help page); Memory is limited on Free per the pricing page. - Paid from: not checked (not verified: pricing page did not show prices on 2026-10-02) - Best at: Setting a standing tone once and having it applied to every chat. - The catch: You describe your style yourself, within a limit: 1,500 characters on Free and Go, 5,000 on Plus, Pro, Business and Education. The help page does not say it measures your writing. - Platforms: web, desktop, ios, android - Source: [OpenAI Help Center: ChatGPT custom instructions](https://help.openai.com/en/articles/8096356-chatgpt-custom-instructions) ### Claude instructions and skills Account-wide "Instructions for Claude", per-project instructions and skills that can "apply communication patterns based on your own writing or preferences". - Link: https://support.claude.com/en/articles/10185728-understanding-claude-s-personalization-features - Free tier: yes. A free plan exists, with Pro at the price shown (Claude pricing page). - Paid from: $17 per month (billed annually; $20 monthly) (checked 2026-10-02; USD) - Best at: Letting you build repeatable behaviours, such as a tone or format, that Claude applies when you turn them on. - The catch: You supply and maintain the description of your style; the support article does not say Claude measures it from samples. That article is inconsistent on whether project instructions need a paid plan. - Platforms: web, desktop, mobile - Source: [Claude Help Center: Understanding Claude's personalization features](https://support.claude.com/en/articles/10185728-understanding-claude-s-personalization-features) ### Jasper Brand Voice A marketing platform whose Brand Voice feature "analyzes your content's tone of voice" and applies tone and formatting rules. - Link: https://www.jasper.ai/pricing - Free tier: not verified. A 7-day free trial. - Paid from: $59 per seat per month (Pro, billed yearly) (checked 2026-10-02; USD; $69 per seat billed monthly) - Best at: Keeping a team's writing on-brand, with Brand Voices and knowledge assets; style guides are on the Business plan. - The catch: Aimed at marketing teams: the Pro plan includes 2 Brand Voices, and style guides are on the Business plan. - Platforms: web, api - Source: [Jasper: pricing](https://www.jasper.ai/pricing) ### Grammarly Humanizer voice profiles A humaniser that rewrites AI text with four preset tones or a custom voice, available with a free account. - Link: https://www.grammarly.com/ai-humanizer - Free tier: yes. A free account unlocks the Humanizer agent with custom voice profiles (vendor page). - Paid from: not checked (not verified: Grammarly Pro price not checked) - Best at: Free voice options and wide app coverage, including Google Docs and Microsoft Office. - The catch: It rewrites existing AI text rather than drafting from your brief, and Grammarly says it is not intended to bypass AI detectors. Full functionality needs Grammarly Pro. - Platforms: web, chrome, ios, android, desktop - Source: [Grammarly: Free AI Humanizer](https://www.grammarly.com/ai-humanizer) ### ScriptGrain (ours) Measures the rhythm, vocabulary, structure and habits in your own writing on 45 reference points, builds a voice profile and drafts new content in it, scoring each draft against it. - Link: https://scriptgrain.com/ - Free tier: yes. Free: one voice profile, all 45 points, one draft, and connecting ChatGPT or Claude. No card needed. - Paid from: £12 per month (Writer; £115 a year) (checked 2026-10-02; GBP including VAT) - Best at: Writing in YOUR measured voice, with a voice-match score on every draft and Voice Brain memory of what you have already covered. - The catch: The free plan gives one voice profile, one analysis and one draft; more drafts need a paid plan. Its homepage asks for 120 words or more of your own writing to start. - Platforms: web, api - Source: [ScriptGrain: home page](https://scriptgrain.com/) ## How they compare ### If you want to set a tone once, free ChatGPT custom instructions and memory suit you here. Custom instructions are on all plans and apply to every chat, so you set the tone once and it carries through. The catch is that you're the one describing your style, and there's a limit: 1,500 characters on Free and Go, 5,000 on Plus, Pro, Business and Education. Memory is limited on Free too, going by the pricing page. And the help page doesn't say it measures your writing. It follows what you tell it. ### If you want a team's writing kept on-brand Jasper Brand Voice is the one aimed at this. It analyses your content's tone of voice and applies tone and formatting rules, so a team's writing stays consistent; style guides are on the Business plan. What you give up is money: it's built for marketing teams, the Pro plan includes 2 Brand Voices, and you get a 7-day free trial. ### If you want free voice options in your usual apps Grammarly's Humanizer voice profiles fit if you write in Google Docs or Microsoft Office. A free account unlocks four preset tones or a custom voice, and the coverage across apps is wide. But it rewrites AI text that already exists. It doesn't draft from your brief, so you need something else for the first version. Full functionality needs Grammarly Pro too. ### If you want a voice measured from your own writing Our own ScriptGrain is built for this. It measures the rhythm, vocabulary, structure and habits in your writing on 45 reference points, builds a voice profile, then scores each draft against it, which is the difference from the chatbots: you don't write the description yourself. The catch is the free plan, which gives you one voice profile, one analysis and one draft, and more drafts need a paid plan. Its homepage also asks for 120 words or more of your own writing to start. ### If you would rather write your own instructions in Claude Claude's account-wide instructions, per-project instructions and skills can "apply communication patterns based on your own writing or preferences", and Claude has a free plan, with Pro at $17 per month billed annually ($20 monthly). But the support article doesn't say Claude measures your style from samples. As with ChatGPT, you write the description and you keep it up. ### When paying is worth it Paying makes sense when the free route stops doing the job. For a team, that's Jasper, at $59 per seat per month billed yearly ($69 billed monthly) after the 7-day trial. For one person who wants a measured voice and more than a single draft, our own ScriptGrain's Writer plan is £12 a month (£115 a year, including VAT). ## What to watch for ChatGPT's pricing page didn't show prices when we checked, so confirm the cost before you plan around it. Grammarly says its Humanizer is not intended to bypass AI detectors. If that's why you're looking at it, it isn't the tool for that. Then there are the quieter limits. ChatGPT's character caps mean a long, detailed style description might not fit on Free or Go. Jasper's trial is 7 days. With the chatbots, the upkeep is on you: you supply and maintain the description of your style. And Claude's support article is inconsistent on whether project instructions need a paid plan, which is worth checking before you rely on them. ## How we checked On 2 October 2026 we read the vendor pages listed under sources: OpenAI's custom instructions and Memory help pages and ChatGPT pricing page, Claude's personalization help article and pricing page, Jasper's pricing page, Grammarly's humaniser page, and the home and pricing pages of ScriptGrain, which is ours. The old Claude "styles" help article returned a 404, so we describe only the instructions and skills it now documents. ChatGPT prices didn't show on its pricing page. We did not hands-on test any of these. ## If none of these fit The free way is to paste two or three samples of your own writing into a chatbot and ask it to describe your style, then save that description as custom instructions. The page for our own ScriptGrain says it measures the rhythm, vocabulary, structure and habits that make writing yours, which is what that manual description tries to capture. ## Also typed as - ai that writes in my style - ai that writes in your voice - ai that writes in your style - ai that writes essays in your style - is there an ai that writes like a human ## Related questions - [Is there an app that can humanize ai text?](https://isthereathing.com/an-app-that-can-humanize-ai-text/) - [Is there a tool that detects ai writing?](https://isthereathing.com/a-tool-that-detects-ai-writing/) - [Is there an ai that can help me write a book?](https://isthereathing.com/an-ai-that-can-help-me-write-a-book/) ## Sources - [Claude Help Center: Understanding Claude's personalization features](https://support.claude.com/en/articles/10185728-understanding-claude-s-personalization-features) (checked 2026-10-02) - [Claude: pricing](https://claude.com/pricing) (checked 2026-10-02) - [OpenAI Help Center: ChatGPT custom instructions](https://help.openai.com/en/articles/8096356-chatgpt-custom-instructions) (checked 2026-10-02) - [OpenAI Help Center: Memory in ChatGPT](https://help.openai.com/en/articles/8590148-memory-faq) (checked 2026-10-02) - [Jasper: pricing](https://www.jasper.ai/pricing) (checked 2026-10-02) - [Grammarly: Free AI Humanizer](https://www.grammarly.com/ai-humanizer) (checked 2026-10-02) - [ScriptGrain: home page](https://scriptgrain.com/) (checked 2026-10-02) - [ScriptGrain: pricing](https://scriptgrain.com/pricing) (checked 2026-10-02) - [ChatGPT: pricing](https://openai.com/chatgpt/pricing/) (checked 2026-10-02) ## Questions people ask ### Can ChatGPT write like me? You can save style instructions in ChatGPT's custom instructions, up to 1,500 characters on Free and Go and 5,000 on paid plans. Memory can also use past chats where enabled. ### Can Claude write like me? Claude's instructions apply account-wide, and its skills can apply communication patterns based on your own writing or preferences. You write and maintain them yourself. ### What is the difference between style instructions and a voice profile? Style instructions are rules you write. ScriptGrain instead measures your own writing on 45 reference points and scores drafts against the result. ### Is there a free option? Yes. ChatGPT custom instructions are on all plans, Claude has a free plan, Grammarly's custom voice needs only a free account, and ScriptGrain's free plan includes one voice profile and one draft.