Paleointensity.org is an online, open source, application to analyze paleointensity data produced by the most common paleointensity techniques. Our application currently supports four different methods: thermal Thellier (all variations), microwave Thellier, pseudo‐Thellier, and the multispecimen protocol. Data can be imported using a variety of input file formats such as ThellierTool files, the generic PmagPy file format, and a number of lab‐specific formats. The data for the individual paleointensity methods are visualized by the relevant graphs and parameters, which are updated dynamically while interpreting the data. Beyond manual interpretation, Paleointensity.org features an autointerpreter for specimen level Thellier‐type data. Interpretations and data can be exported to csv and MagIC files. Moreover, it is possible to export the local storage containing all data, saved interpretations, and settings. This file can be shared among researchers or attached to a paper as supporting information. Because of its many features and ease of use, Paleointensity.org is a major step forward in enhancing an open paleomagnetic community in which data can be shared, checked, and reused in line with the findable, accessible, interoperable, and reusable data principles. Plain Language Summary Obtaining reliable estimates of the past strength of Earth's magnetic field is very challenging. Over the past decades, different techniques were developed to obtain information on the paleointensity of Earth's magnetic field. Here we present a new online, open source application to ease and standardize the interpretation of the most commonly used paleointensity techniques. Paleointensity.org supports the import and export of multiple file formats, including the format used by the global paleomagnetic database MagIC. This promotes and supports the findable, accessible, interoperable, and reusable use of data by the paleointensity community worldwide. Key Points We present a new online, open source, application for the interpretation of the most commonly used paleointensity techniques Paleointensity.org currently supports Thermal Thellier, Microwave Thellier, pseudo‐Thellier, and Multispecimen data Data can be imported and exported in several formats, including MagIC files, to promote the FAIR use of data