By GrammarlySan Francisco, United States1 product across 1 category
Built for this. Works inside the apps you already write in rather than a separate window, which is why it actually gets used. Grammar, tone and clarity in place.
Free plan
Yes
Writing without spelling and grammar mistakes, tone detection, and 100 AI prompts for
Month to month
$30/mo
Pro
Billed yearly
$12/mo
$144 a year, Pro plan −60%
Watch out: Better at fixing than composing. It smooths writing toward a neutral register, which is not always what you want.
All plans (3)
Plan
Price
What you get
Free
$0
Free tier: writing without spelling and grammar mistakes, tone detection, and 100 AI prompts for generating text
Pro
$30/mo · $12/mo yearly
rewriting whole sentences in a click, tone adjustment, unlimited personalised suggestions, and plagiarism and AI-text detection. It opens on a 7-day free trial with nothing to pay on the day and a reminder two days before it ends
Enterprise
Custom
adds proactive AI across the apps you work in, dedicated support, bring-your-own-key encryption, custom roles and permissions, and data loss prevention
By MicrosoftRedmond, United States1 product across 1 category
Built for this. Sits inside Word, Excel, Outlook and Teams, so it works on the documents and meetings a company already has. The closest thing to AI that needs no change of habit.
Free plan
No
Paid from the start
Month to month
$25.20/mo
Microsoft 365 Copilot Business, sold to teams rather than to one person
Billed yearly
$21/mo
Microsoft 365 Copilot Business plan −17%
Watch out: An add-on rather than a standalone purchase: the enterprise Copilot seat is $30 a user a month on top of a qualifying Microsoft 365 licence you must already hold, and Copilot Chat is only included if you already pay for an eligible subscription. Agents need an Azure subscription on top again.
All plans (5)
Plan
Price
What you get
Microsoft 365 Copilot Business
$25.20/mo · $21/mo yearly
an add-on to an existing Microsoft 365 plan rather than a subscription in its own right
Microsoft 365 Business Standard with Copilot
$28.20/mo · $23.50/mo yearly
the Microsoft 365 apps across devices with Copilot built in
Microsoft 365 Business Premium with Copilot
$38.40/mo · $32/mo yearly
the same again with the advanced security tier
Microsoft 365 Copilot, the enterprise seat
$30/mo yearly
Microsoft 365 Copilot Chat
included at no additional cost for Microsoft Entra users on an eligible Microsoft 365 subscription, though agents need an Azure subscription and Copilot Studio capacity is bought prepaid
Two things separate these and both are on every card.
Fit
Whether a tool is built for this job, a strong fit for it, or
able to do it without that being its focus.
Free plan
Whether there is a tier you can keep using rather than a
trial that expires.
The order
Fit first, then a free plan, then alphabetical. There is
no score, no weighting we decline to publish, and nothing on this site a company can buy.
Questions
What is the best ai for legal writing?
There is no single answer, which is why this page lists 4 rather than one: Claude, ChatGPT, Grammarly, Microsoft 365 Copilot. 4 of them are built for this kind of work rather than able to do it. Start with a free one.
Which of these have a free plan?
3 of the 4: Claude, ChatGPT, Grammarly. Free means a real free tier you can keep using, not a trial that expires.
How was this list chosen?
By hand, from the 750 products this site tracks, and it is checked against the catalogue on every build — a product renamed or removed breaks the build rather than quietly disappearing from here. Nothing on this site can be paid for: no listing, no position, no wording.
