The government has been urged to do more to ensure social media giants harness technology to enforce a new law banning sexual predators from contacting children online.
A total of 1,316 cases were recorded in England and Wales in six months after the offence of Sexual Communication with a Child was introduced in April last year.
Facebook, Snapchat and Instagram were the most common sites used by offenders to target youngsters, accounting for 63% of all cases where the communication method was recorded.
Before the law was introduced, police could not intervene until groomers tried to meet their victims face-to-face.
Now, the NSPCC is calling upon ministers to force social media companies to build upon existing technology to flag up potential abuse.
The charity argues that algorithms are already used by social networks to tailor adverts to users and detect illegal content, and that an existing voluntary code of practice does not go far enough.
The NSPCC said in a statement: "Where children are speaking to adults online, it's possible for grooming language to be automatically picked up using algorithms in order to send an alert to children."
It said that such an alert would allow children to think twice about continuing the conversation and offer them support if needed.
Algorithms are currently used to flag up images of child abuse, hate speech and extremist material.
Girls aged between 12 and 15 were the most likely to be targeted by predators, although the youngest victims were just seven years old.
Tony Stower, the NSPCC's head of child safety online, said: "Despite the staggering number of grooming offences in just six months, Government and social networks are not properly working together and using all the tools available to stop this crime from happening.
"Government's Internet Safety Strategy must require social networks to build in technology to keep their young users safe, rather than relying on police to step in once harm has already been done.
"If government makes a code for social networks that is entirely optional and includes no requirement for platforms to tackle grooming, this is a massive missed opportunity and children will continue to be put at risk."
Following the introduction of the law, then-Justice Secretary Liz Truss said: "In a world of mobile phones and social media, our children are ever more vulnerable to those who prey on their innocence and exploit their trust.
"The best way of protecting our young people from the evils of child abuse is to stop it happening in the first place."
The NSPCC now wants to see a mandatory code put in place across social networks to tackle grooming overseen by an independent regulator.
It said social networks must face consequences if they fail to adhere to the code and must regularly publish data on reports of grooming, their response times and the action taken.
The highest proportion of online grooming cases were record in the north of England, where 444, or 33.7%, of cases were logged.
This was followed by the southeast, where 208 cases were reported.