Kate and Gerry McCann said they would persevere in their mission to find their missing daughter, who vanished aged three while the family were on holiday in Portugal.
The couple used the official Find Madeleine Campaign Facebook page to thank supporters for their “persisting solidarity” as it “gets harder to know what to say or write” as the years go on following her disappearance.
The police investigation to find the missing girl, who disappeared from the family’s holiday apartment in Praia da Luz in May 2007, has cost more than £11 million.
The post, written on behalf of Mr and Mrs McCann, said: “It gets harder to know what to say or write as each anniversary of Madeleine’s abduction approaches then passes.
“Life is full and busy which helps but Madeleine is still missing and she is still dearly missed.
“Information continues to come in (incredible as it may seem after so long, although we are grateful for that) and work goes on. Perseverance and hope remain.”
Mr and Mrs McCann, from Leicestershire, added: “Thank you to everyone who continues to support us and wish us, especially Madeleine, well.
“After 11 years such warmth and persisting solidarity is truly remarkable, and at the same time a real tonic and boost to our spirit. We couldn’t bear for Madeleine to be forgotten or to become just a ‘story’.
“She is a real person and still our ‘little girl’ and as we always have, we will endeavour to do whatever it takes to find her.
“Thank you so much for staying with us on this mission.”
Last week, the Home office confirmed it was to provide an extra £154,000 for Scotland Yard to extend the hunt by another six months.
Mr and Mrs McCann had hired a series of private investigators, who failed to find any trace of her, and Portuguese police closed their investigation 15 months after she went missing.
In April 2017, Met Police Assistant Commissioner Mark Rowley said detectives were still following a critical lead, but he refused to reveal details of the line of inquiry being pursued.