PHASTER is a faster and more efficient version of the PHAST phage search tool. PHASTER improves upon PHAST by using software and hardware enhancements, making it 4.3 times faster in analyzing bacterial genomes. It processes a typical bacterial genome in 3 minutes from raw sequence data or 1.5 minutes with a pre-annotated GenBank file. PHASTER also includes automated database optimization, improved handling of multiple queries, and the ability to perform automated look-ups against 14,000 previously annotated bacterial genomes. The web interface has been completely rewritten, offering a more modern, user-friendly, and visually appealing experience. PHASTER is available online at www.phaster.ca. PHASTER was developed in response to the increasing popularity and demand for phage identification tools. PHAST, introduced in 2011, became one of the most popular tools for prophage identification in bacterial genomes. However, as the number of sequenced bacterial and phage genomes grew, PHAST's performance became increasingly strained. PHASTER addresses these challenges through improved software, hardware, and database optimizations. PHASTER uses BLAST+ for faster and more efficient sequence comparisons, and it has a larger computing cluster with 112 CPU cores, compared to PHAST's 32. This allows PHASTER to process data much faster. PHASTER also supports metagenomic data and offers a 'quick query check' feature that allows it to quickly identify previously annotated sequences. The user interface has been completely rewritten, using modern technologies like JavaScript and Ruby on Rails, making it more robust and user-friendly. PHASTER's performance improvements are evident in its faster processing times and higher accuracy in identifying prophages. It achieves a higher sensitivity and positive predictive value compared to PHAST, especially when analyzing previously annotated genomes. PHASTER is now capable of handling assembled contig sets from metagenomic data and offers several useful interface enhancements for viewing and exploring its output. Overall, PHASTER is significantly faster and more efficient than PHAST, with performance improvements that make it suitable for handling the increasing volume of data in bacterial genomics. It is now a more robust and user-friendly tool for identifying and annotating prophage sequences in bacterial genomes.PHASTER is a faster and more efficient version of the PHAST phage search tool. PHASTER improves upon PHAST by using software and hardware enhancements, making it 4.3 times faster in analyzing bacterial genomes. It processes a typical bacterial genome in 3 minutes from raw sequence data or 1.5 minutes with a pre-annotated GenBank file. PHASTER also includes automated database optimization, improved handling of multiple queries, and the ability to perform automated look-ups against 14,000 previously annotated bacterial genomes. The web interface has been completely rewritten, offering a more modern, user-friendly, and visually appealing experience. PHASTER is available online at www.phaster.ca. PHASTER was developed in response to the increasing popularity and demand for phage identification tools. PHAST, introduced in 2011, became one of the most popular tools for prophage identification in bacterial genomes. However, as the number of sequenced bacterial and phage genomes grew, PHAST's performance became increasingly strained. PHASTER addresses these challenges through improved software, hardware, and database optimizations. PHASTER uses BLAST+ for faster and more efficient sequence comparisons, and it has a larger computing cluster with 112 CPU cores, compared to PHAST's 32. This allows PHASTER to process data much faster. PHASTER also supports metagenomic data and offers a 'quick query check' feature that allows it to quickly identify previously annotated sequences. The user interface has been completely rewritten, using modern technologies like JavaScript and Ruby on Rails, making it more robust and user-friendly. PHASTER's performance improvements are evident in its faster processing times and higher accuracy in identifying prophages. It achieves a higher sensitivity and positive predictive value compared to PHAST, especially when analyzing previously annotated genomes. PHASTER is now capable of handling assembled contig sets from metagenomic data and offers several useful interface enhancements for viewing and exploring its output. Overall, PHASTER is significantly faster and more efficient than PHAST, with performance improvements that make it suitable for handling the increasing volume of data in bacterial genomics. It is now a more robust and user-friendly tool for identifying and annotating prophage sequences in bacterial genomes.