Grammarly
Could a prompt do it?

Polished emails, proposals and website copy in your own voice.

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01 / THE DECISION

Before you unsubscribe.

Consider cancelling if…

You mainly pay for occasional rewrites and tone edits, and are happy to paste drafts into your AI assistant.

Keep the app when…

Keep Grammarly if you rely on suggestions where you type, plagiarism checks or shared style controls.

Try the prompt on a real task first. A free plan may be enough. Confirm your renewal date and save anything you need before changing your plan.

02 / THE NUMBERS

Subscription vs prompt.

Grammarly Pro≈ $12.00 / month

Listed plan rate

Advertised starting rate; confirm billing term at checkout.

USD · 20 independent prompt runs / month · reference comparison
Model	Per prompt	Reference difference / month*
GPT-6.1 Sol · Standard	$0.0090–$0.015020 runs: $0.1800–$0.3000	$11.70–$11.82≈ 97.5–98.5%
Claude Sonnet 5.5 · Standard	$0.0090–$0.015020 runs: $0.1800–$0.3000	$11.70–$11.82≈ 97.5–98.5%
Claude Opus 5.5 · Standard	$0.0180–$0.030020 runs: $0.3600–$0.6000	$11.40–$11.64≈ 95.0–97.0%
DeepSeek V4.1 Flash · peak	$0.0012–$0.001920 runs: $0.0234–$0.0378	$11.96–$11.98≈ 99.7–99.8%
DeepSeek V4.1 Flash · off-peak	$0.0006–$0.000920 runs: $0.0117–$0.0189	$11.98–$11.99≈ 99.8–99.9%
GPT-6 Astra · Standard	$0.0450–$0.075020 runs: $0.9000–$1.5000	$10.50–$11.10≈ 87.5–92.5%
Claude Fable 5.1 · Standard	$0.0450–$0.075020 runs: $0.9000–$1.5000	$10.50–$11.10≈ 87.5–92.5%

*Reference bill less estimated API tokens. Additional AI charges, tools and review time are excluded here. Enter your actual costs in the personal calculator. Savings require being able to stop paying for the whole subscription. Assumptions

BRING THIS

A draft, your audience and one example of your preferred voice.

CHECK THIS

Check names, numbers and every change that could alter the meaning.

Choosing an assistant: GPT-6.1 Sol / Claude Sonnet 5.5 — value starting points. Claude Opus 5.5 — candidates for harder work. DeepSeek V4.1 Flash — budget candidates. GPT-6 Astra / Claude Fable 5.1 — specialist options. Compare a real task and the tools in your account; no guide claims equal results across models. Choices, limits and sources · Checked 30 September 2026.

Act as my business copy editor. Edit the draft below for [audience] with the goal of [desired action]. Use [tone] and [NZ/UK/US] English. Match the voice of the example, without copying its claims.

Preserve all facts, commitments, figures and qualifications. Do not invent evidence or make the offer stronger than the source supports. Flag ambiguous statements instead of guessing.

Return: (1) a ready-to-use revision; (2) a short table of material edits and why you made them; (3) claims I should verify. Keep the revision under [word count] words. If essential context is missing, ask up to three focused questions before editing.

DRAFT: [paste]
VOICE EXAMPLE: [paste]

What the estimate covers.

One editing response with a short draft. Assumes 1,500 input tokens and 600–1,200 output tokens. Follow-up turns, reasoning and tools can increase the cost.

Monthly savings use 20 independent first responses. Chat app subscription fees are separate from API token charges.

Sources & next steps.

Official Grammarly product and pricing page ↗

Model rate sources and calculation method ↗

Pricing baseline: 11 September 2026. Grammarly and Otter rechecked 13 September. Unverified plan prices remain labelled as assumptions.

Replacement suitability is our editorial assessment, not a vendor claim or a measured benchmark.