Tone Checker
Paste an email, Slack message or essay paragraph and see how it reads: formal or casual, warm or cold, direct or hedged, calm or tense. Free, runs in your browser, nothing is uploaded.
Your message
This is a rule-based estimate, not a verdict. The checker matches words and phrases; it cannot see your history with the reader, the thread above, or the fact that you and your manager have joked like this for years. A tense score on a message to a close teammate may be fine. A calm score on a message to an upset client may still land badly. Read the result as a second opinion, then use your own judgement.
About this tone checker
How this email tone checker works
Paste your draft and the tool scans it for four things. Formality comes from greetings and sign-offs, contractions, slang and exclamation marks. Warmth compares positive words against negative ones. Directnesscounts commands against hedges like “just”, “maybe” and “if possible”. Tensionlooks for the tells of a message written while annoyed: capitals, “??”, “clearly”, “again”, “you never”, and the passive-aggressive stock phrases. Everything runs in your browser, so nothing you paste leaves your device.
Scores are measured per 60 words, not per message, so a long email and a two-line Slack reply are judged on the same scale. There is no account, no extension and no paste limit, and the numbers update as fast as you can edit, which makes it easy to change one sentence and watch the tension meter drop.
When to run a message through it
Before you reply to something that annoyed you. Before you email a client, a recruiter, a landlord or anyone senior. Before you send a reminder for the third time. Also useful the other way round: if your writing keeps getting called blunt, check whether your directness sits near the top of the scale while warmth sits near the bottom.
Routine notes rarely need it. Scheduling, status updates and “got it, thanks” replies are fine on a read-through. The messages worth checking are the ones with something at stake: chasing money, saying no, giving feedback, correcting a mistake that was not yours, or writing to someone who has already misread you once.
What tone in writing actually means
Tone is the attitude your word choices carry, separate from the facts you are reporting. “The report is late” and “I still don't have the report” carry the same fact and different attitudes. Tone lives in small choices: contractions, hedges, who is the subject of the sentence, whether you name a person or a task. Readers pick it up in a second, which is why a rushed one-line reply so often reads colder than you meant.
Voice and tone are not the same thing either. Voice is how you always sound; tone is how you sound in this one message. A brand, or a person, can keep one voice and still shift tone between a launch announcement and an apology. The meters above measure tone, the thing that moves message to message.
Four edits that fix a cold or sharp email
Most tone problems come from the same handful of habits, and the fixes take under a minute:
- Cut the stock phrase.Delete “as per my last email”, “friendly reminder” and “just to clarify”. Replace each with the plain fact and a date.
- Change the subject of the sentence.“You didn't send the file” becomes “I don't have the file yet”. Same information, no finger pointing.
- Put the ask in one short sentence. Near the top, with a deadline. Buried requests are what make people hedge and repeat themselves.
- Add one human line.A six-word opener such as “Thanks for turning this around quickly” moves the warmth meter more than a paragraph of politeness at the end.
Two more habits worth breaking: capitals for emphasis, which read as shouting to almost everyone, and the double question mark, which turns a question into an accusation.
The same request written three ways
One message, three tones. The request never changes; only the framing does.
Blunt“The deck is due Friday. Send it.” High directness, low warmth. Nothing rude in the words, but with no context it reads like an order.
Hedged“Just wondering if you might possibly have a chance to look at the deck at some point, no rush!” Warm and friendly, and the deadline has vanished. Four softeners in one sentence make the request sound optional.
Clear“Could you send the deck by Friday lunchtime? Happy to take the pricing slide off your plate if that helps.” Warm, direct, calm. The ask has a date, and the offer of help does the softening that four hedges were trying to do.
What a good score looks like, by context
| Where it is going | Formality | Warmth | Directness | Tension |
|---|---|---|---|---|
| Slack or Teams, your own team | 20–45 | 50+ | 55–80 | under 25 |
| Everyday work email | 40–60 | 50–70 | 55–80 | under 25 |
| Client or customer email | 55–75 | 55–70 | 50–70 | under 20 |
| Complaint or escalation | 55–75 | 40–60 | 65–85 | under 35 |
| Cover letter or recruiter reply | 60–80 | 55–75 | 55–75 | under 15 |
| Essay or academic writing | 70+ | any | any | under 10 |
| Text message to a friend | under 35 | 60+ | any | under 20 |
These are rough bands, not rules, and they come from how this tool weighs words rather than from any published standard. A message outside them can still be the right message. Use them to spot the gap between what you meant and what you wrote, then decide for yourself.
Tone checker, Grammarly tone detector, or an AI tone checker?
This checker: word patterns, in your browser
Rules catch the reliable signals: hedges, capitals, accusatory phrasing and around twenty stock passive-aggressive phrases. It names each phrase, says why it lands badly and offers a plainer line. It is free, needs no login, works on any text you can paste, and never sends your draft anywhere. What it cannot do is read the thread above your reply or spot sarcasm.
Grammarly tone detector: labels and rewrites
Grammarly mixes rules with machine learning and labels your writing with tone words rather than scores, drawing on a set of roughly forty tones. It needs about 90 characters before it activates, and it wants an account plus a browser extension or app. Sentence-level tone rewrites sit on the paid plans. If you already write inside Grammarly all day, it is the more convenient option; if you want a number you can compare between drafts without installing anything, paste it here.
AI tone checkers: context, at a cost
An AI tone checker sends your text to a model, which handles sarcasm, long threads and in-jokes far better than any word list. The trade is that your draft leaves your device, checks are usually capped or paid, and the answer changes slightly each time you run it. Worth it for a message that could cost you a client. Overkill for a Tuesday reminder. Semrush, despite the searches, has no standalone email tone checker; its writing extension rewrites content in a chosen tone instead.
A human: still the best tone checker
For anything genuinely sensitive, a colleague who knows the reader beats every tool on this list. The cheap version of the same check is reading your draft out loud. If a sentence would feel strange to say to the person's face, it will read strangely on screen.
Other things people call a tone checker
“Tone checker” means several unrelated things. This page only checks the tone of writing. If you came looking for one of these, you want a different tool:
- Skin tone checker. Finds your undertone from a photo to match foundation, hair colour or clothing. That is colour analysis, not writing.
- Guitar, music or vocal tone checker. Tuners and pitch analysers that measure frequency from a microphone, used for intonation and singing practice.
- Chinese or Mandarin tone checker. Pronunciation drills for the four pinyin tones, where tone changes the meaning of the word itself.
- Fluke tone generator and probe. Network hardware for tracing a cable through a wall by the sound it makes. Nothing to do with language at all.
Frequently asked questions
How do I check the tone of my email?
Paste the whole draft, greeting and sign-off included, into the box at the top. You get four meters and a one-line read within a second. Then do the human check that no tool does for you: read it out loud. Anything you would not say to the person's face is the line to rewrite.
Is this tone checker free?
Yes, free and online with no sign-up and no limit on how many messages you check. The analysis happens in your browser, so your email text is never sent to a server.
How much text does it need?
At least four words, but the scores settle down from about two sentences upward. Short messages are noisy because one word moves a meter a long way, so a three-word Slack reply will swing further than a full email. For comparison, the Grammarly tone detector waits for roughly 90 characters before it says anything at all.
Can an essay checker catch tone?
Partly. A grammar checker flags mistakes; a tone checker flags impressions. Rules catch the reliable signals, like hedging, capitals and stock passive-aggressive phrases, which is most of what goes wrong in an email or an essay intro. What rules miss is sarcasm, running jokes and anything that depends on the sentence before.
Can I use it as an essay tone checker?
Yes, and the formality meter is the one to watch. Academic writing wants it high, and the usual culprits dragging it down are contractions, slang and exclamation marks. Paste a paragraph at a time rather than a whole essay: a single section gives you a cleaner read than an average across ten pages. Warmth and directness matter far less in coursework than they do in email.
How is this different from the Grammarly tone detector?
Grammarly labels your writing with tone words drawn from a set of about forty, mixing rules with machine learning, and it needs an account plus an extension or app. Sentence-level tone rewrites are a paid feature. This one is a web page: no install, no login, nothing uploaded. It gives you numbers you can compare across drafts, and it names the exact phrases that cause trouble along with a plainer replacement for each.
Does Semrush have an email tone checker?
No. Semrush is an SEO and content platform, and plenty of people search for a Semrush email tone checker that does not exist. Its AI writing extension can rewrite text in a chosen tone, which is a different job from telling you how your draft already reads. If you want a reading rather than a rewrite, this page does it without an account.
Can AI detect tone in text?
An AI tone checker reads context better than word lists do, so it handles sarcasm and long threads more sensibly. It also costs an API call per check and sends your text somewhere. For a quick sanity check before you hit send, word patterns catch the common problems. For a sensitive message, ask a colleague.
What counts as a passive-aggressive phrase?
Phrases that stay polite on the surface while pointing at the reader: "as per my last email", "just to clarify", "friendly reminder", "not sure if you saw", "with all due respect", "going forward". The checker highlights them in your text and gives you a plainer version. The fix is almost always the same: say the plain thing, with a date.
Why does my friendly email score cold?
Usually because warmth is built from words, and short efficient messages contain few of them. A three-line update with no thanks, no name and no context reads flat even when you were in a perfectly good mood writing it. Adding the recipient’s name and one line of acknowledgement is normally enough to move it.
Does it work for text messages and Slack, not just email?
Yes. Short messages give noisier scores because a single word moves the meter more, so give it at least a couple of sentences. Chat is more casual by default, so a low formality score on Slack is normal; watch the tension meter instead.
Is this a skin tone, guitar tone or Mandarin tone checker?
No. This tool only checks the tone of writing. A skin tone checker matches undertones from a photo, a guitar or vocal tone checker measures pitch from a microphone, a Chinese tone checker drills the four pinyin tones, and a Fluke tone generator traces network cables. Different meanings of the same word, different tools.