ScriptGrain vs ChatGPT

ScriptGrain measures your voice as 45 attributes from writing you have already published and holds every draft to them. ChatGPT's custom instructions apply the handful of preferences you can state about yourself to a general-purpose assistant.

The actual difference

Custom instructions rely on what you can articulate about your own style, and most of a voice is habits you cannot see: function-word patterns, punctuation cadence, clause ordering. ScriptGrain measures 45 attributes from writing you have already published, including those unconscious markers, then scores every draft against the measured profile.

Custom instructions cost nothing on any ChatGPT plan, and the paid tiers buy a better model and higher limits rather than a better memory of your voice. ScriptGrain is paid (from £12/month) because it does a different job: measuring your voice and holding every draft to the measurement.

ScriptGrainChatGPT
Entry price£12/mo (Writer, 1 voice profile)Free (custom instructions are on every plan)
Free tierYes, See your own voice profile. No card.ChatGPT's free tier includes custom instructions
Voices on entry plan1 (3 on Operator, £29/mo)One set of custom instructions per account
How the voice is built45 measured style attributes, extracted from writing you have already publishedA settings box holding roughly five self-reported preferences: tone, response length, communication style, preferred language, and free-text instructions. It applies what you can articulate about your style to every chat.

ChatGPT figures read from their pricing page on 9 August 2026.

Where ChatGPT is stronger

The default AI writing surface for most people. Custom instructions are its personalisation layer: a settings box that applies your stated preferences to every chat.

If you want one assistant for research, code, brainstorming and quick drafts, ChatGPT is that product, and for casual replies where voice does not matter, custom instructions are plenty.

Questions

Is ScriptGrain better than ChatGPT?

They solve the problem differently. Custom instructions rely on what you can articulate about your own style, and most of a voice is habits you cannot see: function-word patterns, punctuation cadence, clause ordering. ScriptGrain measures 45 attributes from writing you have already published, including those unconscious markers, then scores every draft against the measured profile. If you want one assistant for research, code, brainstorming and quick drafts, ChatGPT is that product, and for casual replies where voice does not matter, custom instructions are plenty.

How much does ChatGPT cost compared with ScriptGrain?

ChatGPT's entry plan is Free (custom instructions are on every plan), with this free tier: ChatGPT's free tier includes custom instructions. ScriptGrain starts at £12/month (Writer, 1 voice profile) with a free plan: See your own voice profile. No card. ChatGPT figures read from their pricing page on 9 August 2026.

Does ChatGPT learn my writing voice?

A settings box holding roughly five self-reported preferences: tone, response length, communication style, preferred language, and free-text instructions. It applies what you can articulate about your style to every chat. ScriptGrain instead measures 45 style attributes from writing you have already published, and scores every draft against that measured profile.

Other comparisons

ScriptGrain · Why ScriptGrain · Sample voice profiles · The Journal · Support