ChatGPT is the fastest way to get a resignation letter draft — give it your role, your last day, and the reason (or none at all), and it returns a usable letter in one pass. Claude tends to hold a more consistently professional, measured tone across the full letter, which matters more than it sounds since a resignation letter is short but every sentence gets read closely. Grammarly is the final pass that catches anything reading as too blunt, too emotional, or accidentally unprofessional before you actually send it. A resignation letter has one job: end things cleanly, in writing, without saying anything you'll regret being on record. All three tools help with that; the difference is speed versus tone control versus a safety-check pass.
Where each one actually wins
ChatGPT produces a complete, standard-format resignation letter from a short prompt — your job title, your employer, your last working day, and whether you want a reason stated. For most people, most of the time, this is genuinely all a resignation letter needs to be, and ChatGPT gets there in one pass.
Claude is worth using specifically when the situation is even slightly delicate — leaving on bad terms, a short-notice departure, or a role where you'll want a strong reference later. Its longer-context, more consistent tone-holding means a two-paragraph letter reads as deliberately measured rather than templated.
Grammarly isn't a drafting tool here — it's the check before you hit send, catching a sentence that reads more emotional or more blunt than you intended, which is the single most common way a resignation letter goes wrong.
Quick comparison
| Tool | Core job | Starting price | Best fit |
|---|---|---|---|
| ChatGPT | Fast, standard-format draft | Freemium | Most resignations — clean, simple exits |
| Claude | Measured, consistent tone | Freemium | Sensitive departures, keeping the door open |
| Grammarly | Tone and grammar check | Freemium | The final pass before sending, every time |
What no AI tool should decide for you
Never let AI draft the *reason* for leaving if you're at all unsure what to say — a generic "pursuing a new opportunity" is almost always the safer default than an AI-generated explanation that sounds more detailed or more critical than you meant. Also don't let AI decide your notice period or final working day; that's a factual, contractual detail you need to get right yourself, not something to leave to a plausible-sounding guess.
FAQ
Is it unprofessional to use AI to write a resignation letter? No — a resignation letter is a formal, fairly standardized document, and using AI to get the structure and tone right quickly is no different from using a template, which people have done for decades.
Should a resignation letter include why I'm leaving? Only if you want to — a short, neutral letter stating your last day is completely sufficient and often the safer choice. Save detailed feedback for an exit interview, if you're asked and choose to give it.
How short should a resignation letter actually be? Very short — a few sentences stating your intent to resign, your last working day, and (optionally) a thank-you line, is standard. AI tools sometimes over-write; cut back to this length regardless of what the first draft gives you.
Can I use the same letter for a bad and a good departure? No — adjust the tone specifically for your situation. Claude's more measured default tends to work better for a complicated exit; ChatGPT's faster, more neutral default is fine for a clean, amicable one.
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*Ratings and pricing reviewed monthly. Last updated August 2026.*
Bogdex · Founder & editor, woska
Bogdex builds and curates woska, testing AI tools against real workflows to judge which ones actually save time rather than which have the longest feature list.