One product for the whole writing day.
Detect, rewrite, check, and finish a draft in one place — and read our detector's measured error rates before you trust its score. Built for writers who want fewer tabs and more finished drafts.
Why We Built This
Tools are overpriced
Many AI writing tools can feel expensive for basic features. We try to keep entry points simpler, with a free tier plus paid plans for heavier usage.
Privacy is an afterthought
Text you submit to a writing tool is processed for that request and is not used to train models. The AI Detector goes further: it is scored on our own servers and your text reaches no third party at all. The details, including which tool sends what where and what we do retain, are in the privacy policy.
Too many tabs
You shouldn't have to stitch together separate products just to draft, check, rewrite, and ship a piece of writing. Coda One keeps that one workflow under one roof.
"Free" doesn't mean free
Sign-up walls, daily limits, and watermarks are common frustrations. We try to keep the writing workflow direct: no signup for the detector, no daily cap on it, and published error rates instead of an accuracy claim.
What We Offer
One check-then-fix loop
AI Detector, AI Humanizer, AI Rewriter, and Grammar Checker — the whole set is on Free Tools, and all four are in the Chrome extension.
Research and comparisons
Our measured detector error rates, head-to-head tool comparisons, and the blog.
In August 2026 we retired our PDF, image, video, and developer utility lines, then the generators, converters and one-off checkers that sat outside the writing loop. Those pages say so rather than quietly disappearing.
Our Principles
Free means free
The AI Detector has no daily limit and no signup. The AI Humanizer, AI Rewriter and Grammar Checker give you 3 runs a day before anything is asked of you.
Privacy first
Signed out, your text is processed and not kept. Signed in, the input and result are saved to your history so you can find them again — you can delete any entry, or the whole account. Cookie-free analytics via Plausible.
Low-friction access
We try to keep tool access direct and reduce unnecessary setup steps where possible.
Transparent pricing
No hidden fees. SaaS subscriptions fund AI API costs. Affiliate links are clearly disclosed. No ads, ever.
How We Make Money
Transparency matters. Here's exactly how we sustain this project while keeping most tools free.
SaaS subscriptions
Paid plans for AI writing tools help cover API costs and fund development. Check the pricing page for current plan details.
Affiliate commissions
Referral fees from tool links. Does not affect rankings — reviews are independent and clearly disclosed.
Our Team
Built by developers and AI practitioners
Coda One is built in-house by a small, UK-based independent team. We use these tools in production every day. When something doesn't work the way we'd want, we fix it. Every tool is built from scratch, not white-labeled.
Ready to try?
Start with any tool and explore the workflow that fits your use case.