DeepFeather
中文

REPLACEMENT BRIEF

ai writing

Can AI replace Grammarly?

EDITORIAL ANSWERKINDACatalog estimate

You can pair LanguageTool with an LLM rewrite button for your own writing. Grammarly's moat is being present everywhere you type, with inline suggestions, tone detection, and team style guides.

Run text through LanguageTool plus an LLM rewrite/tone checker, expose a browser extension or local editor.

Build the personal version →

AT A GLANCE

price
$30/mo
listed annual price
$360/yr
replaceable scope
Run text through LanguageTool plus an LLM rewrite/tone checker, expose a browser extension or local editor.
build time
multi-day
Build promptcatalog estimate

the prompt

Catalog estimate
Build me a personal writing checker to replace Grammarly. Requirements:

- Grammar engine: LanguageTool running locally via its official Docker image;
  grammar checks never leave my machine.
- A local web page (Node + Express, binds to localhost): paste text, see
  LanguageTool issues underlined with hover explanations, click a suggestion
  to apply it.
- An LLM rewrite pane (key in .env) with three buttons: tighten, friendlier,
  formal. Show a diff against my original before I accept anything.
- A personal dictionary file (dictionary.txt) of names and jargon to never
  flag, passed to LanguageTool on every check.
- CLI mode: `check <file.md>` prints issues with line numbers, exits nonzero
  if any, so it can run as a git pre-commit hook on docs.
- Everything local except the optional LLM call; no accounts, no telemetry.
- Out of scope: a browser extension and inline suggestions inside Gmail,
  Docs, or Slack. This is a destination I paste into, that is the honest
  trade against Grammarly.
- README: Docker setup for LanguageTool, the roughly 1 GB of RAM it wants,
  and where the LLM key goes.
Copy or open in an agent

The prompt stays readable first. Choose a launch option when you are ready.

$ open in your agent (prompt prefilled, you press enter) or copy it raw · suggest a correction

what AI can build

Run text through LanguageTool plus an LLM rewrite/tone checker, expose a browser extension or local editor.

Editorial catalog estimate · not a completed build

The honest tradeoff

why people still pay

what you lose

inline suggestions everywhere

document/email integrations

tone/brand controls

enterprise admin

polished false-positive handling

Start with existing software

prior art · use these instead of building, if you'd rather

LanguageToolOpen-source grammar and style checker and the primary Grammarly-like prior art.↗

EVIDENCE LEDGER

What this page can prove

The verdict judges replaceability. The evidence level records what DeepFeather actually checked.

Read the methodology →
evidence level
Catalog estimate

Editorial catalog estimate · not a completed build

replacement boundaryRun text through LanguageTool plus an LLM rewrite/tone checker, expose a browser extension or local editor.

known limits · inline suggestions everywhere; document/email integrations

editorial reviewreviewed

BUILD FEEDBACK

Did you try this build?

Report the outcome. Submissions enter a manual evidence queue and never auto-upgrade the verdict.

LanguageTool
$19.90/mo · ai writingYESCanva
$18/mo · designKINDAFigma
$20/mo · designNOT REALLY

questions

Can AI replace Grammarly?

Possibly for a narrower core workflow, but this catalog judgment is not a verified build. Expected gaps include: inline suggestions everywhere, document/email integrations. Validate the prompt against your own acceptance criteria before committing.

How much does Grammarly cost?

Grammarly is listed at about $30/month (Pro, checked 2026-07-30), or $360 per year. This is a pricing reference, not evidence of a completed replacement or realized savings.

What do I lose by replacing Grammarly?

Honestly: inline suggestions everywhere; document/email integrations; tone/brand controls; enterprise admin; polished false-positive handling. If any of those are load-bearing for you, keep paying.

Is there an open-source alternative to Grammarly?

Yes — LanguageTool (Open-source grammar and style checker and the primary Grammarly-like prior art.). Using prior art is also a valid exit; the prompt is for when you want it exactly your way.