Similarity 2.4

Find and remove duplicate music and image files from hard disk
4.2  (6 votes)
2.4.2 (See all)

If you value your audio and photo collections enough to make sure that your archive contains one copy of each file only, and that this copy is the one with the best quality possible, Similarity is your duplicate finder. This high-end software tool takes duplicate search to the next level. Its advanced algorithm performs a multi-pattern analysis of all suspect files to provide you with the exhaustive and accurate data you need to make fully-informed decisions.

Forget about searching for duplicates using the file names, sizes, and extensions as the only criteria – Similarity will check those and then will analyze the audio bit and sample rates, the compression rate, the format used, the ID3 tags, the image quality, and whatever other technical parameters may help this tool to alert you about all those similar files clogging your disks. Checking all these possible matching criteria is neither an easy task nor a quick one. Depending on the size of your photo and music collections and of your PC’s processing speed, checking for duplicates among a few thousands of files may take from half an hour to a few hours. Excellence has a price, and in the case of Similarity, you pay that price in time. You can always increase the threshold values for some comparison criteria to speed up the analysis, but then some possible duplicates may be involuntarily overlooked.

This is a tool for serious collectors who take a clean and neatly organized audio and image collection very seriously. When comparing audio files you cannot rely on their external data only – not even a byte-by-byte comparison would render accurate results when comparing an audio track and its apparently identical transcode. That is why Similarity prefers to rely on their “acoustic fingerprint” to make sure that they’re the same song before presenting them as dupes. Images are no different when it comes to formats, compression rates, or resolutions, and that is why Similarity will check not only all the usual suspects but also their content.

The result is an exhaustive list of “similar” audio and image files, with accurate levels of coincidence in tags, content, and precision (all expressed in percentages) for the audio. Besides, you will be informed about their duration, the content of their ID3 tags, their size, etc. A deeper analysis of the musical composition will provide you with precise information about their bit rate, sample rate, spectrum analysis, amplitude values, clipping, silent blocks, beats, etc. As for the images, you’ll be informed of the percentage of coincidence in the content, the resolution, the format, the size, etc., to help you clear your photo collection of coinciding files. As one would expect from such a thorough tool, the list of candidates is usually rather extensive. To save time and to help you make the most sensible decisions you can turn on the Automark option, which will highlight all the files that Similarity considers dupes of inferior quality. You can then delete all of them in one go or unmark those you want to check more closely. Tip: the program’s built-in audio player, complete with a small waveform graph, can be of great help.

Similarity is not the usual duplicate finder. Its high level of excellence and accuracy guarantees that no likely dupe candidate goes unnoticed. It may not be as straightforward, fast, and easy to use as most of its competitors, but all of them pale in comparison when it comes to cleaning up your audio and photo collections.

Francisco Martínez
Editor rating:

Review summary


  • Exhaustive multi-pattern analysis
  • Analyzes the quality and properties of the audio
  • Support for all popular audio and image file formats
  • Offers the best possible option
  • Built-in audio player and tag editor
  • Compares audio tags
  • Precise categorization of all possible candidates


  • Its deep analysis slows down the process
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