Convert FITS files online for free
The converter easily converts your FITS file to various formats - free and online. No SAOImageDS9 or or other Raster Image software needed.
The converter also works in reverse, so you can convert other "Scientific Data Container" formats to FITS without using software like SAOImageDS9 or a similar tool.
The .FITS (Flexible Image Transport System) file is the open standard for storing, transmitting, and manipulating scientific data, particularly within astronomy. Endorsed by NASA and the IAU, it is the primary format used by observatories like Hubble and James Webb to capture celestial phenomena. Unlike standard images, a .FITS file contains extensive metadata (headers) and raw photometric data in multi-dimensional arrays, often recording light well beyond the visible spectrum.
While indispensable for science, .FITS files are notoriously difficult for general users to handle. They cannot be opened by standard image viewers on Windows or macOS. Furthermore, the raw data is often "linear" and high-dynamic-range (16-bit or 32-bit floating point), meaning the image may appear completely black until it is processed with specific "stretch" algorithms to map the data to a visible range. To share these cosmic visuals or include them in presentations, users must convert them. For web viewing, convert to JPG or PNG (after tone-mapping). For high-quality printing or further artistic editing in software like Adobe Photoshop, convert to TIFF. Just drag and drop to convert.guru to visualize the cosmos without installing complex scientific toolkits.
Use Convert.Guru to open and convert your FITS file.
Users also converted FIT, FTS, NPY, ZIP, PAK, MOC, VTP, PWB, TIFF, JPG, CSV, PNG and RAW files.
If you want to convert FITS file to CSV or ASCII, you can use SAOImageDS9 or similar software from the "Astronomical Scientific Imaging" category. In the File menu, look for Save As… or Export….
To convert files to FITS, try SAOImageDS9 or another comparable tool in the "Astronomical Scientific Imaging" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our FITS converter.