Difference between Heartfelt and Sincere

HEARTFELT vs SINCERE: ADJECTIVE

Open and genuine; not deceitful
Characterized by a firm and humorless belief in the validity of your opinions
Being without hypocrisy or pretense; true.
Pure; unadulterated.
Meant truly or earnestly.
Earnest; meaning what one says or does; truthful.
Honest; free from hypocrisy or dissimulation.
Being in reality what it appears to be; having a character which corresponds with the appearance; not falsely assumed; genuine; true; real.
Whole; perfect; unhurt; uninjured.
Pure; unmixed; unadulterated.
Not feigned or affected; genuine.

Felt in or prompted by the heart; profoundly felt; deeply sincere: as, heartfelt joy or grief; heartfelt congratulations or cheers.
Sincerely earnest

Sound; whole; unbroken; without error, defect, or injury.
Pure; unmixed; unadulterated; free from imitation; good throughout: as, sincere work.
Having no admixture; free; clear: followed by of.
Unalloyed or unadulterated by deceit or unfriendliness; free from pretense or falsehood; honestly felt, meant, or intended: as, a sincere wish; a sincere effort.
Free from duplicity or dissimulation; honest in speech or intention; guileless; truthful; frank.
Morally pure; undepraved; upright; virtuous; blameless.
Synonyms and Fair, Open, etc. (see candid); Cordial, Sincere, etc. (see hearty), unfeigned, undissembling, artless, heartfelt.
Open and genuine
Not deceitful

Frank, Believable, Forthright, Candid, Genuine, Wholehearted, Profound, Fervent, Passionate, Impassioned, Poignant, Devout, Dear, Earnest, Sincere

Heart whole, Bona fide, Dear, Serious, Solemn, Devout, True, Unfeigned, Earnest, Fervent, Wholehearted, Cordial, Honest, Genuine, Heartfelt

Frank, Believable, Forthright, Candid, Genuine, Wholehearted, Profound, Fervent, Passionate, Impassioned, Poignant, Devout, Dear, Earnest, Sincere

Heart whole, Bona fide, Dear, Serious, Solemn, Devout, True, Unfeigned, Earnest, Fervent, Wholehearted, Cordial, Honest, Genuine, Heartfelt

Sincere wishes on your anniversary, Mom and Dad!
One integral and sincere confession within nine days.
Please believe in my feelings of sincere friendship.
Please be reflective and sincere in your discussion.
Crown patrons has often been read as sincere.
Finallymy most sincere thanks to my wife Lauren.
He is childlike, simple, humble, sincere, and forgiving.
Heather Price is sincere, laid back and professional.
Those sincere men who told them so believed it because an earlier generation of sincere men had told them the very same thing.
Her narratives combine sincere anxiety and sincere compassion.