CoolCroco vs FastRawViewer

Checked against fastrawviewer.com on 4 September 2026

Both of these exist for the same moment: you are back from a shoot with several hundred raw files and you have to decide which ones survive. They go about it differently, and neither is simply better than the other. This page is written by CoolCroco's developer, so read it knowing that. It is kept factual on purpose.

The short answer

What FastRawViewer does that CoolCroco does not

• A real raw histogram, drawn from the unprocessed sensor data, so you can see whether the scene fitted inside the camera's dynamic range. CoolCroco has no histogram of any kind.
• Over and underexposure warnings and statistics computed from the raw, which show what is actually clipped rather than what merely looks clipped after processing.
• Focus peaking, marking the in-focus edges directly on the picture.
• Shadow boost, lifting the shadows so you can evaluate what is down there before deciding to keep a frame.
• Per-channel views, a black and white preview, and a contrast curve.
• Propagating an exposure or white balance correction across a series of similar frames.
• It is made by LibRaw LLC, Iliah Borg and Alex Tutubalin, who also wrote LibRaw. That is the library CoolCroco uses to decode raw files. Their raw handling is the reference the rest of us build on, and it is worth saying so plainly.

What CoolCroco does that FastRawViewer does not

• Holds the whole folder decoded in memory. After the first pass nothing is decoded again, so going backwards through a shoot is exactly as fast as going forwards.
• Searches a shoot by what is in the pictures. Type motorcycle, or stars over a lake, and the frames that match come to the front. It runs entirely on your own computer.
• Finds duplicates: the frames that are the same photograph, gathered into groups with one picked out to keep.
• Finds timelapses and bursts, and files each run into its own folder in a single undoable step.
• Filters a folder down to part of itself: one lens, one ISO, one afternoon, the five-star frames. Every option says how many frames it holds.
• Writes keywords, copyright and the rest of the IPTC fields, and removes EXIF and location data with a backup so it can be restored.
• Runs on Linux, as well as Windows and macOS.

Where they are the same

More than a comparison page usually admits. These are not differences, and it would be misleading to present them as any.

• Both decode the actual raw file rather than showing you the JPEG the camera embedded in it.
• Both cull by moving files rather than deleting them. FastRawViewer moves or copies into folders and keeps a rejected subfolder so the deletion decision can wait. CoolCroco moves into Approved and Rejected beside the originals, with undo.
• Both write ratings and labels into XMP, where Lightroom, Bridge and Capture One read them.
• Both have a grid or thumbnail view for going through a shoot as a contact sheet.
• Both are fast. They spend the speed differently: FastRawViewer decodes quickly on demand, at a stated 6 to 8 frames per second for 16 to 36 megapixel files. CoolCroco decodes the folder once, in the background, and then does not decode again.

Price and platforms

One more thing worth saying

These two are not really competing for the same hour of your day. FastRawViewer answers a question about the file. CoolCroco answers a question about the photograph. Plenty of photographers would be well served by owning both, and if the raw histogram is what you need, twenty-four dollars is not much to pay for the people who wrote the decoder.

Every claim about FastRawViewer on this page was read off fastrawviewer.com on 4 September 2026. Software changes. If something here has gone out of date, or if you think it is unfair, write to [email protected] and it will be corrected.