Grammarly vs Writesonic: Which AI Writing Tool Is Better in 2026?

Grammarly

From $12

Writesonic

From $16

Quick verdict

Overall pick: Writesonic

Pick Grammarly if your priority is everyday editing and clarity at a lower per-seat starting price of $12, and you want a plagiarism checker and brand voice memory. Pick Writesonic if you produce SEO blog posts or run an agency: it adds copy templates, SEO optimisation, multilingual output and a public API, though it lacks a plagiarism checker. Grammarly's per-seat billing scales with headcount, while Writesonic's flat billing does not.

Grammarly's entry plan ($12) is 25% cheaper than Writesonic's ($16).
Grammarly charges per user while Writesonic uses a flat price, so Writesonic gets relatively cheaper as your team grows.
Both offer a free plan, so you can test them side by side at no cost.
Only Grammarly offers: plagiarism checker.
Only Writesonic offers: copy templates, seo optimisation, multilingual output, public api.

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Cost calculator

Team size: 5 users

Tool	Monthly	Yearly
Grammarly · per user	$60.00	$720
Writesonic · flat	$16.00	$192

Based on entry-level paid plans. Prices change, so check the vendor before you buy.

Which one should you choose?

If you need…	Pick	Why
SEO blog production	Writesonic	Writesonic has SEO optimisation and copy templates; Grammarly has neither.
Everyday editing and proofreading	Grammarly	Grammarly is positioned for grammar, tone and clarity and includes a plagiarism checker, which Writesonic lacks.
Agencies serving multilingual clients	Writesonic	Writesonic supports multilingual output and a public API; Grammarly supports neither.
Budget-conscious small team	Grammarly	Grammarly starts at $12 per seat versus Writesonic at $16 flat, though Grammarly's cost scales with each seat.
Building custom content workflows	Writesonic	Writesonic offers a public API; Grammarly does not.

Feature comparison: Grammarly vs Writesonic

Feature	Grammarly	Writesonic
Free plan	✅	✅
Starting price	$12 /user/mo	$16 /mo
Copy templates	—	✅
Brand voice / style memory	✅	✅
Plagiarism checker	✅	—
Browser extension	✅	✅
SEO optimisation	—	✅
Team workspaces	✅	✅
Multilingual output	—	✅
Public API	—	✅

Highlighted rows are where the tools differ.

Pros and cons

Grammarly

Lower starting price at $12 per seat
Includes a plagiarism checker
Brand voice / style memory and browser extension included
Team workspaces supported

No copy templates
No SEO optimisation mode
No multilingual output and no public API

Try Grammarly →

Writesonic

SEO optimisation mode and copy templates
Multilingual output and a public API
Brand voice, browser extension and team workspaces included
Flat billing rather than per-seat

No plagiarism checker
Higher starting price at $16
Founded in 2020, a shorter track record than Grammarly's 2009

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At a glance

Grammarly

Writing assistant for grammar, tone and clarity.

Founded 2009 · From $12 · 4/8 tracked features

Best for: everyday writing, editing

See Grammarly alternatives →

Writesonic

AI writer focused on SEO content.

Founded 2020 · From $16 · 7/8 tracked features

Best for: SEO blog posts, agencies

See Writesonic alternatives →

FAQ

Is Grammarly cheaper than Writesonic?

Grammarly starts at $12 per seat, while Writesonic starts at $16 on flat billing. Grammarly's per-seat model means total cost rises with each added user.

Does Writesonic have a plagiarism checker?

No. Writesonic does not list a plagiarism checker; Grammarly does.

Which tool offers SEO optimisation?

Writesonic has an SEO optimisation mode. Grammarly does not.

Does Grammarly offer a public API?

No. Grammarly does not list a public API, while Writesonic does.

Which tool supports multilingual output?

Writesonic supports multilingual output; Grammarly does not.

Related comparisons

Data last reviewed: pending verification. All AI Writing tools →