People look for a sincerely synonym for two different jobs. At the bottom of a letter, kind regards, best regards, best wishes and respectfully replace it. Inside a sentence, such as I sincerely hope, the swaps are genuinely, truly and honestly.
You get both uses here, plus a sign-off chart from relaxed to formal, sentence rewrites, a few British and American differences, and the antonyms.
Swatch at a glance
Best sign-offs
kind regards, best regards, best wishesBest adverbs
genuinely, truly, honestlyPart of speech
Adverb (also a set closing)Most formal
respectfully, yours faithfully, cordiallyMost casual
thanks, cheers, take careAntonyms
insincerely, half-heartedly, falselyWatch out
Honestly at the start of a sentence can sound defensive or annoyed. Use genuinely when you want warmth.
Picking a closing line by situation
| Closing | Tone | Good for |
|---|---|---|
| Kind regards | polite, warm | most work email, first contact |
| Best regards | polite, neutral | clients, colleagues in other teams |
| Best wishes | friendly | people you know, congratulations |
| Respectfully | very formal | officials, judges, a complaint letter |
| Yours truly | formal, a bit old-fashioned | printed letters, US |
| Yours faithfully | formal, British | letters to Dear Sir or Madam |
| Best | brisk | quick replies in an ongoing thread |
| Cheers | casual, mainly British and Australian | friends and close coworkers |
Why each sincerely synonym sounds different
On the strip above, a breezy thanks sits at one end and a stiff respectfully at the other. Thanks works when you just asked for something. Best is short and safe, though some readers find it curt. Kind regards adds a little warmth. Yours truly feels like paper and ink. Respectfully sits at the top and tells the reader you are writing up to someone in authority, or that you disagree with care.
British writers often keep Yours sincerely for letters that open with a name and Yours faithfully for unnamed readers. In the US, plain Sincerely covers both.
Swapping the adverb inside a sentence
- I sincerely apologize for the delay becomes I truly apologize for the delay.
- We sincerely hope you can join us becomes we really hope you can join us in a friendly note.
- She sincerely believed the plan would work becomes she genuinely believed the plan would work.
- Thank you sincerely for your help becomes thank you warmly for your help or thank you from the heart.
- He spoke sincerely about his mistakes becomes he spoke candidly about his mistakes.
See truly synonyms, genuine synonyms and deeply synonyms for related words.
Cover letters and job emails
For a cover letter, Sincerely is still the standard close and is never wrong. If you want a change, Kind regards or Best regards is safe. Avoid Cheers and Thanks a bunch, which sound too relaxed for a stranger who might hire you.
A graduate ends an application with "Thanks, Sam." It reads like a note to a roommate. Changing the line to "Kind regards, Sam Lee" with a phone number underneath looks finished and polite, and it costs two words.
More advice on work phrasing lives in our resume and job words.
Careful with these
Seriously means not joking, not with good intentions, so I seriously hope can sound like a threat. Honestly as an opener (Honestly, I tried) often signals frustration. Faithfully alone, outside the fixed closing, means loyally. And Love as a sign-off belongs only with family and close friends.
Antonyms of sincerely
The direct opposite is insincerely. Half-heartedly describes effort without real interest, grudgingly describes doing something unwillingly, and hypocritically means saying one thing while doing another.
- He apologized half-heartedly and left.
- She grudgingly agreed to the change.
For more linking and closing language, visit transition words, then check ways to say thank you for the line before your sign-off.
Frequently asked questions
Is kind regards less formal than sincerely?
Slightly. Sincerely is the classic letter closing, while kind regards is the most common closing in business email. Both are polite.
How do I close a very formal letter without sincerely?
Respectfully and Yours faithfully are the most formal. Respectfully suits letters to officials, and Yours faithfully is a British choice when you do not know the reader's name.
Is Sincerely yours the same as Yours sincerely?
Yes, the meaning is the same. Sincerely yours is more common in the US, and Yours sincerely is more common in the UK.
Which adverb can replace sincerely in an apology?
Truly and deeply work well: I truly apologize, I am deeply sorry. Genuinely also fits but sounds a little more casual.
Can I end a work email with just Best?
Yes, in quick replies with people you already write to. When writing to someone new, Best regards or Kind regards feels warmer.
If someone acts without sincerity, what adverb describes it?
Insincerely is the direct antonym. Half-heartedly and grudgingly describe actions done without real feeling.