FastStone Photo Resizer is a Windows program for converting and renaming images in batches. It can also resize, crop and rotate pictures, change their color depth, and add text or watermarks. You build a list of images, choose the changes and an output destination, then process the selected group. The software is free for personal and educational use; commercial use requires a purchased license.
Batch Conversion
The file browser and drag-and-drop support provide ways to collect images for a conversion job. The input list has controls for adding files, removing selections and clearing the list. An output-format selector chooses the type of files to create, while the output-folder setting determines where they are written.
Resizing changes image dimensions, cropping removes unwanted areas, and rotation changes orientation. These operations can be applied across a batch instead of opening and editing each picture separately. Color effects and color-depth changes adjust the images’ appearance or color representation. Text, watermarks and border effects add visible elements to the resulting pictures.
FastStone Photo Resizer includes a conversion preview for checking the chosen changes. Options can be saved and loaded for another job, so a recurring set of transformations does not have to be configured from scratch. Multithreading allows several images to be processed simultaneously.
Image Renaming
Batch renaming gives a collection a numbered filename sequence. Search-and-replace can change matching text in existing filenames, which serves a different purpose from assigning a new sequence: it retains the remaining parts of each name. A renaming preview lets you inspect the proposed names before applying them.
Image Formats
FastStone Photo Resizer reads JPEG, JPEG2000, PNG, GIF, BMP and TIFF, along with formats such as PCX, TGA, WMF, EMF, ICO, CUR, PPM, HEIC and WEBP. Its output choices are JPEG, JPEG2000, PNG, GIF, BMP and TIFF. Reading a format therefore does not mean it is also available for saving.
HEIC input depends on Windows Imaging Component codecs on Windows 10 or 11.
