We provide a range of dynamic services to help IWF Members safeguard their business from the upload, sharing, storage and sale of criminal child sexual abuse images and videos.
In 2025, more than 200 Members from across technology and internet-based industries used our services to prevent the exploitation of their services.
Our Members share our vision to put an end to child sexual abuse imagery online and trust the expertise of our analysts, our technical innovation and unique datasets.
Through IWF membership, organisations gain access to a curated suite of services designed to help them detect, remove and prevent child sexual abuse images. This include the IWF Hash List, URL List, Keywords List and Non-Photographic Imagery (NPI) List.
Our dynamic URL List provides a comprehensive list of webpages where we have confirmed the presence of child sexual abuse images or videos where the URLs link to or were found advertising such content. Since each URL (Uniform Resource Locator) identifies a unique webpage, image link, or website address, we can be precise about the exact location of the criminal imagery to ensure we never over-block a legitimate website.
We provide a list of these webpages to our Members who can then block or filter this material, affording greater protections to their users and to the children depicted in the criminal imagery.
During 2025:
Criminal URLs on the list will depict a whole range of children, all ages, sexes and varying categories of severity of sexual abuse.
We issue notice and takedown requests (also known as takedown notices) for websites hosted in the UK only. When content is hosted outside the UK, we notify the relevant international hotlines and law enforcement agencies to enable action to be taken locally. With agreement, our Hotline also supports the removal of international child sexual abuse material by following up on IWF notifications and contacting the hosting provider directly. This is an additional service we provide to limit the global availability of child sexual abuse imagery.
We conduct daily checks of the IWF URL List to confirm whether criminal content remains live or has been taken down. Any URLs found to no longer contain this criminal content are removed the list the same day, ensuring it remains accurate and up to date. The list is updated twice a day, with URLs added or removed as content is identified or taken down.
Keeping advertising dollars away from illegal and harmful content is essential to maintaining trust in the digital ecosystem. By integrating into our technology signals developed by the IWF, such as the URL lists, we help advertisers avoid high-risk environments, protect their brand and reduce the risk of criminal activity being funded. This partnership underscores the power of combining advanced technology with trusted expertise to give brands greater confidence in their digital investments.
We use our own software, IntelliGrade, which generates a unique digital hash using advanced mathematical algorithms. These hashes are automatically created when our assessors complete the image-level assessment and the imagery is classified as criminal child sexual abuse. Each criminal image or video receives its own unique hash, which is then added to our Hash List. This list is regularly updated and shared with trusted partners across industry and law enforcement. We also support safety tech companies by enabling them to generate their own proprietary hashes from the images we hold, within a secure environment. This allows them to improve their detection technologies without accessing or storing the images themselves.
By integrating the list into their systems, organisations can automatically detect and block previously identified child sexual abuse imagery by matching uploads against our database of known hash values. This prevents the need to view, store or re-share the original content and prevents further revictimisation of the children depicted in this criminal imagery.
This rapid matching process prevents thousands of known criminal images from being uploaded to the internet again.
To date we have 3,224,085 criminal hashes on our list.
To learn more about our Hash List, visit our All-time hash data page.
Most organisations don’t realise the risk that can exist on corporate devices until it becomes a crisis. In recent years we’ve seen cases where illegal material has been discovered on workplace devices in environments where trust and safeguarding are critical. Our technology gives organisations a responsible way to identify those risks early, without compromising privacy. By working with the IWF, we’re helping organisations take proactive steps to protect children, protect their employees and protect their reputations
Our Non-Photographic Imagery URL List identifies webpages hosting non-photographic representations of child sexual abuse, such as computer-generated images (CGI), cartoons, manga images and drawings.
URLs included on the list have been assessed by IWF analysts as breaching UK legislation. Prohibited non-photographic imagery is assessed under a separate legal framework (Section 62 of the Coroners and Justice Act 2009) to indecent images that fall under the Protection of Children Act 1978 and Section 160 of the Criminal Justice Act 1988.
While non-photographic imagery is outlawed in the UK, this isn’t the case for many other jurisdictions around the world.
If we find this content hosted in the UK, we issue a notice to the hosting provider, who removes it. For companies based elsewhere in the world, we’re unable to seek the removal of this content. Therefore, our NPI URL List provides a vital lifeline to support companies who want to prevent access to this content.
As of 2025, several international technology companies use this list to protect their services for their customers.
At DNSFilter, we rely on all the assistance we can get from our partners at the IWF. By leveraging IWF's NPI data list, we are able to cover an ever increasing swathe of child sexual abuse material. This is of increasing importance as GenAI-made material is on the rise. We continue to look forward to close collaboration with the IWF, ensuring we provide the best coverage possible against child sexual abuse material. We are proud that this partnership enables us to give our customers the peace of mind that this content is always blocked on their network.
Our Keyword List brings together terms, phrases and codes developed by offenders to disguise and circulate criminal child sexual abuse material online. This intelligence is shared with IWF Members to:
Our analysts are constantly identifying and evaluating new terminology to add to the list. Each month new additions are tested, with each term undergoing rigorous quality assurance before upload. The list continues to expand through our collaboration with law enforcement agencies and partners across the technology and internet industry.
We are proud to join the IWF as a new Member as it is a defining moment in our mission to build safer digital systems around safeguarding and safer recruitment. By embedding the IWF’s URL and Keywords lists into our platform, we’re giving organisations the ability to take preventative, intelligent steps against potential safeguarding threats. This is safeguarding by design.
Some readers may find the following descriptions distressing, please feel free to skip this section.
As analysts, we understand that some of the darkest parts of the internet exist on some of the world’s most popular platforms. We recognise the internet isn’t confined by borders, and the intelligence that we collect shouldn’t be either. Whether it be a new term popping up, a platform shift, or a special way offenders communicate, this global intelligence feeds directly into one of our most hands-on tools: the Keywords List.
The Keywords List isn’t static; it evolves as we learn, and only an analyst could understand the full context of some of the keywords we use. Keyword terms are not always obvious, they may be slang words or phrases that pertain to child sexual abuse in one language, but when translated to English mean something entirely different. Understanding keywords and the context behind them provides vital clues for how child sexual abuse material is shared online and this intelligence helps us fight its spread and accessibility.
Keyword intelligence is vital to the work we do in-house at the IWF and also to our wider impact through our Members. This year, the expansion of our keywords service has translated into fewer missed cues and a clearer path for our Members to intervene in the sharing of child sexual abuse that often occurs in plain sight. This service means intelligence evolves beyond stagnant information, and becomes tangible leads to follow, directly protecting children online regardless of their geographical location.
This year has highlighted that as global connectivity grows and reaches more parts of the world, having services and knowledge that span that breadth is essential. Our mission to protect children isn’t confined to those that speak English, and our international understanding has been key in spanning that reach, making sure no child is left behind regardless of where they are. Protecting children in all corners of the earth starts with analysts like us, and our tools reflect that.