ScriptGrain vs WriteBros

ScriptGrain measures your voice as 45 attributes and scores every draft against the measured profile, with the method published. WriteBros rewrites AI drafts to read as human and, on its $79 Pro plan, clones voices from the places you already write; it publishes no voice score.

The actual difference

WriteBros rewrites AI drafts into natural writing and, on Pro, into a trained voice; its pages publish no voice score and no list of what a voice is measured on. ScriptGrain measures your voice as 45 named attributes, scores every draft against the measured profile with the method published, and puts the API and MCP server on every plan, including Free. WriteBros also says every plan passes GPTZero, Turnitin, Copyleaks and ZeroGPT. ScriptGrain's humaniser rescores each pass and makes no detector promise, for the reasons set out in voice preservation vs detector evasion.

WriteBros starts at $12 a month for 30,000 words, and voice cloning, the REST API and the MCP server all sit on Pro at $79 a month. ScriptGrain's Writer plan is £12 a month with one measured voice profile and a score on every draft, and the API and MCP connector come with every plan, including Free.

ScriptGrain is not a replacement for the assistant you already use. It measures your voice from writing you have published and hands that profile to ChatGPT, Claude, Muse or any MCP client through its connector, then scores every draft against it. ScriptGrain makes your AI better at being you.

Connect ScriptGrain to Claude

Every AI voice tool compared: prices, scores and API access, checked

	ScriptGrain	WriteBros
Entry price	£12/mo (Writer, 1 voice profile)	$12/mo (Lite)
Free tier	Yes, See your own voice profile and try one draft. No card.	Free: 1,000 words for the lifetime of the account, up to 1,500 a request, no card and no voice cloning
Voices on entry plan	1 (3 on Operator, £29/mo)	None on Lite. The pricing page puts voice cloning on Pro ($79/mo); one of their landing pages also lists a trained voice on Plus ($30/mo)
How the voice is built	45 measured style attributes, extracted from writing you have already published	You connect the places you already write, such as Slack, Reddit, LinkedIn, X and your documents, and that writing "trains a private model that's yours alone", which they say is never used to train anyone else's. You can train a separate voice for each place you write and switch between them with one click; drafts are then rewritten in that voice. The home page's example sums a voice up in three traits: sentences, tone and style. No voice score, attribute list or scoring method is published.

WriteBros figures read from their pricing page on 25 September 2026.

What WriteBros is built for

WriteBros is a humaniser first. Its own pages call it "the most natural AI humanizer", and the job is plain: take a draft that reads like a machine wrote it and rewrite it so it reads like a person did. The audience is bloggers, marketers, social creators, sales teams, agencies and founders. People who produce a lot of copy, fast, and who already lean on an AI tool to get the first version down.

That shapes everything else about it. The product is tuned for volume. The plans run from a free tier of 1,000 words for the life of the account up to Pro at 1,500,000 words a month, and the allowances are very large. If your week involves cleaning up a steady stream of AI drafts, that matters more than any feature list. Fair enough, it's a real strength, and ScriptGrain doesn't compete on raw word counts.

The voice feature is the second act. On its top plan, WriteBros clones a personal writing voice. Its positioning puts that as an add-on to the humanising, not the centre of the product. Worth knowing before you choose, because "sounds like a person" and "sounds like you" are different jobs.

How WriteBros handles voice

Here's what its pages say. The home page puts it in one sentence: "give it a few things you've written and every draft afterwards comes back in your register." The pricing page, read on 2026-09-30, lists voice cloning and multiple trained voices on Pro only, at $79 a month. An earlier read on 2026-09-25 recorded voices trained from connected sources, with up to 25 trained voices on Pro.

So the mechanic is sample-in, style-out. You give it writing of yours, it trains a voice, and later drafts come back shaped by it. That's a sensible design, and for many people it's enough.

What the pages don't publish is the middle. There's no voice score, no list of what a voice is measured on, and no scoring method. You can't see what the tool decided your voice is. You can't see how far a given draft sits from it. You judge by reading the output and deciding whether it feels right.

That's not a flaw for every buyer. If you trust your own ear and you're the only reader, reading the output is a perfectly good test. It gets harder when you have a team, a client, or a brand guide. Then "feels right" has to survive a second opinion, and there's nothing on the page to point at.

Two more facts frame the Pro plan. The REST API and the MCP server sit on Pro only. And every plan is sold as passing GPTZero, Turnitin, Copyleaks and ZeroGPT, which tells you where the product's centre of gravity is: output that clears a detector first, voice second. Those are the facts as published; how much weight they carry depends on your job.

How ScriptGrain handles voice

ScriptGrain starts from a different question. Instead of "does this read as human?", it asks "how far is this from the voice we measured?"

The measuring comes first. You give it writing you or your brand have already published. It builds a profile of 45 attributes in 8 layers: lexical, syntactic, tone and register, rhetorical, punctuation and format, function words, content patterns, and quirks and cadence. The attributes are named and concrete. Average sentence length and its variance. Contraction rate. Comma density. Semicolon and dash habits. Formality on a 0 to 10 scale. Confidence versus hedging. Opening style, argument structure (evidence-first, conclusion-first, narrative), paragraph openers, pronoun mix. The full list sits in the writing voice attributes reference.

A profile needs at least one sample of 50+ words. The recommendation is three or more pieces and about 3,000 words. Extraction usually takes under a minute; the median was 39 seconds when measured on 2026-09-28.

Then the scoring. Every draft gets a score from 0 to 1 against the profile, what the glossary calls voice match. On-voice drafts typically land between 0.85 and 0.95. Partial matches sit between 0.5 and 0.8. A clearly different voice comes in under 0.45. The score arrives with per-feature deltas, so you see the draft's value against the profile's value. Your draft runs 31 words a sentence against a profile of 17? That's on the page. The method is published in the voice measurement framework.

And the enforcement. Polish revises a draft toward a target score, 0.9 by default. Drafts can be written with the profile as a constraint, and the app learns from the edits a user saves.

One point about delivery, because it gets misread. The profile isn't a prompt you paste. It reaches ChatGPT, Claude, Gemini, Cursor, Meta Muse and any MCP client through the MCP server and the REST API, read live each time. Both come with every plan, including Free. See the API and MCP page for the detail.

The same job in each tool

Take one job. A founder writes a 600-word product update every fortnight. She drafts it with an AI model, and the result is tidy, flat and faintly corporate. Her own writing is clipped, dry, light on adjectives, heavy on short fragments. She wants the update to sound like her, and she wants to know it does.

In WriteBros, she'd connect a few things she's written and train a voice on Pro. She pastes the AI draft in. It comes back rewritten, humanised, and shaped toward her register. She reads it. Some sentences land. One paragraph feels a touch too chatty for her. She edits it by hand and sends it. The whole loop is quick, and the word allowance means she'll never think about limits.

What she can't tell from the tool is how close the result is. The pages publish no score and no attribute list, so her judgement is the only instrument. If she's confident in it, fine. If her co-founder says "this doesn't sound like you", there's no number to settle it.

In ScriptGrain, she'd build a profile from her published writing. The same AI draft goes in, and it gets scored. Say it lands in the partial-match band, somewhere between 0.5 and 0.8. The per-feature deltas show why: sentences far longer than her profile, contractions well below her rate, a formal register where hers sits lower. Polish revises toward 0.9. She reads the revision, edits, saves. The saved edits feed back in.

Same job, different shape. One gives her a faster rewrite. The other gives her a measurement she can argue with, repeat next fortnight, and hand to someone else. Neither is magic. The difference is what you can see.

Which one fits which situation

The right pick depends on what you're actually short of. Time, or certainty.

Pick WriteBros when:

Your main problem is AI drafts that read as machine-made, and volume is high.
You want very large monthly word allowances, and many trained voices on one plan.
You're the only reader and you trust your own ear.
Passing the detectors it names matters to your work.

Pick ScriptGrain when:

You need to show that a draft matches a voice, to a client, an editor or a team.
You want the attributes named, the score published and the method open to inspection.
You want the same profile live in ChatGPT, Claude, your editor and any MCP client, on every plan including Free.
You care about voice drift over months, not just this week's draft.

To be fair, there's a middle case. A high-volume operation that also has a brand guide can reasonably use both, and the last section covers it. If you're undecided, the tools matrix and the pricing page lay out the rest, and /vs has the other head-to-heads.

On price, keep the dates straight. WriteBros' monthly prices were read on 2026-09-30: Lite $12 for 30,000 words, Plus $30 for 450,000 words, Pro $79 for 1,500,000 words with voice cloning, API and MCP. ScriptGrain's Writer plan is £12 a month with one measured voice profile and a score on every draft.

Using ScriptGrain alongside WriteBros

The two don't collide. They do different jobs, and the jobs can run in sequence.

One workable order: generate the draft in whichever model you like, run it through WriteBros to strip the machine flavour at volume, then score the result in ScriptGrain. The score tells you whether the cleanup drifted from your voice or landed near it. If it came back at 0.6, the deltas point at what to fix. If it came back at 0.9, you publish.

Another order: measure first, rewrite second. Score the raw AI draft, see where it sits, then decide whether it needs a heavy humanising pass or a light Polish. That saves you rewriting drafts that were already close.

A few practical notes. Build the ScriptGrain profile from your best published work, not from the drafts you've already run through another tool; otherwise you're measuring a voice that's partly somebody else's rewrite. Three or more pieces and about 3,000 words gives the profile enough to be stable. Keep one profile per voice; a company blog and a founder's newsletter are different voices, and mixing them muddies the deltas.

If you're moving from WriteBros rather than running both, the move is small. Your source writing is the same writing. Point ScriptGrain at it, let the extraction run, and you have a profile in about a minute. What you gain is visibility; what you give up is WriteBros' word volume and its many-voices allowance. That's a real trade, and only you know which side of it your work sits on.

For a quick read on where you stand before committing, the writing style analysis and brand voice consistency checker tools are the places to start. At the end of the day, it's the same question either way: do you want to feel that the writing sounds like you, or know it?

Where WriteBros is stronger

"The most natural AI humanizer." A rewriting tool that turns stiff AI drafts into natural writing, with an AI detector from Lite up and, on Pro, voice cloning: trained voices per platform or per client, callable through a REST API and an MCP server.

It learns from where you already write: connect Slack, Reddit, LinkedIn, X and your documents rather than pasting samples in by hand
Many voices for the money: up to 25 trained voices on the $79 Pro plan, one per channel, client or sales rep, switched with one click
Large word allowances for high-volume rewriting: 450,000 words a month on Plus and 1,500,000 on Pro

If the job is turning large volumes of AI drafts into natural-sounding copy, with a trained voice for each of up to 25 people or channels on one $79 plan, WriteBros is built around exactly that, and it reads your voice from the places you already write. ScriptGrain measures a voice and holds each draft to it. It makes no promise about AI detectors, so if passing one is the requirement, ScriptGrain is the wrong tool.

Questions

Is ScriptGrain better than WriteBros?

They solve the problem differently. WriteBros rewrites AI drafts into natural writing and, on Pro, into a trained voice; its pages publish no voice score and no list of what a voice is measured on. ScriptGrain measures your voice as 45 named attributes, scores every draft against the measured profile with the method published, and puts the API and MCP server on every plan, including Free. WriteBros also says every plan passes GPTZero, Turnitin, Copyleaks and ZeroGPT. ScriptGrain's humaniser rescores each pass and makes no detector promise, for the reasons set out in voice preservation vs detector evasion. If the job is turning large volumes of AI drafts into natural-sounding copy, with a trained voice for each of up to 25 people or channels on one $79 plan, WriteBros is built around exactly that, and it reads your voice from the places you already write. ScriptGrain measures a voice and holds each draft to it. It makes no promise about AI detectors, so if passing one is the requirement, ScriptGrain is the wrong tool.

How much does WriteBros cost compared with ScriptGrain?

WriteBros's entry plan is $12/mo (Lite) (Plus $30/mo; Pro $79/mo carries voice cloning, the REST API and MCP; no annual price shown), with this free tier: Free: 1,000 words for the lifetime of the account, up to 1,500 a request, no card and no voice cloning. ScriptGrain starts at £12/month (Writer, 1 voice profile) with a free plan: See your own voice profile and try one draft. No card. WriteBros figures read from their pricing page on 25 September 2026.

Does WriteBros learn my writing voice?

You connect the places you already write, such as Slack, Reddit, LinkedIn, X and your documents, and that writing "trains a private model that's yours alone", which they say is never used to train anyone else's. You can train a separate voice for each place you write and switch between them with one click; drafts are then rewritten in that voice. The home page's example sums a voice up in three traits: sentences, tone and style. No voice score, attribute list or scoring method is published. ScriptGrain instead measures 45 style attributes from writing you have already published, and scores every draft against that measured profile.