BetterSend vs Grammarly
BetterSend vs Grammarly for Slack messages
Pick BetterSend if you write Slack messages in a second language and want them to come out as natural English in a specific tone, in one click, inside Slack. Pick Grammarly if you want passive spelling and grammar checking everywhere you type, including documents and your phone. The two can run side by side.
Last checked 2026-10-06
Grammarly is a general writing assistant. It underlines mistakes while you type in most text fields, in the browser, in its desktop apps and on mobile, and its Pro plan adds sentence rewrites and tone adjustment. It is built for people who write a lot of English and want a safety net under all of it.
BetterSend is narrower on purpose. It adds Improve, Translate and Explain buttons inside twelve work platforms, Slack included, and a desktop app that works inside the native Slack app. You write the draft in whatever language is fastest for you, choose a tone, and get the message back in natural English. It does nothing until you press the button.
BetterSend is for
Non-native English speakers writing short work messages who want a finished, natural-sounding message in a chosen tone, without leaving Slack.
Grammarly is for
Anyone who wants mistakes flagged while typing across the whole browser, long documents and mobile, mostly in English.
| Feature | BetterSend | Grammarly |
|---|---|---|
| Where it works in Slack | Chrome extension inside Slack in the browser, and a desktop app for macOS and Windows that works inside the native Slack app (a chip in the composer, double-click a received message to translate or explain it). | Grammarly lists Slack as a supported desktop native app through its Windows and Mac apps, and its browser extension attaches to text fields in Chrome, Safari, Firefox and Edge. |
| How it is triggered | On demand only. Nothing happens until you press Improve, Translate or Explain. No underlines while you type. | Passive. Grammarly underlines spelling and grammar issues as you type and shows a tone detector; rewrites are suggested inline. |
| Writing in another language | Write the draft in any language, for example Portuguese, and get natural English back in the tone you picked. "Write in" language and tone are chosen per message. | Grammarly corrects text in the language it is written in (English plus Spanish, French, Portuguese, German and Italian, with more in beta). Turning a Portuguese draft into English means using its in-line translation (a paid feature) and then editing the result. |
| Tones | 13 tones, for example Professional, Friendly, Confident, Diplomatic, Persuasive, Concise, Empathetic and Native Speaker. 3 are free, 10 are Pro. | A tone detector on the free plan. Pro adds one-click tone adjustment; Grammarly's own blog describes rewrites to sound more personable, confident or positive. |
| Translating received messages | Translate button under each received message, into any of 44 languages. Explain button for jargon and idioms. | In-line translation is included in paid plans. Grammarly's translation page lists a 5,000-character limit per translation as of October 2026; check it for the current language count. |
| Free plan | Free plan: 50 actions per month and 3 tones (Professional, Friendly, Grammar fix). | Free plan: spelling and grammar corrections, a tone detector, and 100 AI prompts per month. Full-sentence rewrites and one-click tone adjustment are Pro. |
| Price | Pro is US$ 4.99 per month or US$ 39.99 per year as of October 2026, with all 13 tones and unlimited actions. In Brazil, Pix: 6 months for the price of 4 (R$ 99.60). | Free plan at US$ 0. Pro at US$ 12 per member per month billed annually, or US$ 30 billed monthly, as of October 2026. |
| Beyond chat: documents and mobile | No document editing and no mobile app. Works only inside the 12 supported platforms and the 4 desktop apps. | Works in Google Docs, Microsoft Word, email clients and on iOS and Android keyboards. This is where Grammarly is clearly ahead. |
| Privacy | Message text is never stored; only metadata such as the action type and token count. Nothing is sent on your behalf; you always choose what to send. | Grammarly reads what you type in order to check it. Read its privacy policy for what is stored and for how long; it is not summarized here. |
Verdict
If most of your writing is English and you want it checked everywhere, Grammarly is the better pick, and its free plan covers basic corrections. If your problem is specifically Slack messages written in a second language, where you want a finished message in a specific tone rather than underlines, BetterSend does that job in one click and costs less. Many people keep Grammarly for documents and use BetterSend for chat.
Common questions
Can I use BetterSend and Grammarly at the same time in Slack?
Yes. Grammarly underlines as you type; BetterSend only acts when you press its button. Neither sends anything by itself.
Does Grammarly rewrite a Portuguese draft into English?
Not in one step. Grammarly corrects Portuguese as Portuguese, and its in-line translation is a paid feature you would run separately. BetterSend takes the Portuguese draft and returns English in the chosen tone in one action.
Is BetterSend free?
There is a free plan with 50 actions per month and 3 tones. Pro is US$ 4.99 per month or US$ 39.99 per year as of October 2026.
Find the right tone in one click
Get the desktop app for macOS or Windows, or install the Chrome extension. Same account, the same 13 tones.
Sources
- BetterSend (checked 2026-10-06)
- Grammarly plans (checked 2026-10-06)
- Grammarly Pro (checked 2026-10-06)
- Where Grammarly works (checked 2026-10-06)
- Grammarly support: supported browsers and apps (checked 2026-10-06)
- Grammarly blog: multilingual writing support (checked 2026-10-06)
- Grammarly translation (checked 2026-10-06)
- Grammarly blog: tone rewrite suggestions (checked 2026-10-06)