This digital collection of First World War films at British Pathé contain some 300 films concerning the First World War on a wide range of subjects. You can get small size previews on the website. Digitized versions of the original films can be ordered. The website has an advanced search mode for further research.
In April 2014 British Pathé announced the launch of 85,000 news videos at its YouTube channel. Newsreels from the period 1914-1918 can be found in this collection, too.