Image Perceptual Hash (pHash)

Compute the perceptual hash (pHash) of an image. pHash compresses image content into a 64-bit fingerprint, and similar images produce similar hashes — ideal for duplicate detection and similarity comparison.

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Drop an image or click to upload

PNG, JPG, WEBP, BMP

What Is a Perceptual Hash?

A perceptual hash squeezes an image into a fixed-length fingerprint (64 bits here) while ensuring that visually similar images get similar fingerprints.

It works by extracting low-frequency features in the frequency domain with DCT, ignoring compression, resizing, and slight color shifts that don't affect how we perceive the image.

How to Compute an Image Perceptual Hash

Three steps to compute the pHash of your image:

  • Upload a local image (PNG, JPG, WEBP, or BMP supported).
  • Click Compute Hash to generate the 64-bit hash value.
  • Copy the HEX or binary result for programmatic comparison or archiving.

Tips

  • Different compression or resized versions of the same image produce nearly identical hashes.
  • A Hamming distance under 10-12 bits indicates similar images.
  • Pair this tool with Duplicate Image Finder to deduplicate images in bulk.

Frequently Asked Questions

What is a perceptual hash (pHash)?+
A perceptual hash is a content-aware image fingerprint: the image is shrunk and converted to grayscale, DCT is applied to extract low-frequency features, and a 64-bit hash is produced. Similar images get similar hashes.
How is pHash different from a regular hash?+
Regular hashes like MD5 or SHA are extremely sensitive — changing a single pixel changes the result completely. pHash focuses on the image's overall structure, so recompression, resizing, or slight color tweaks barely affect it.
How do I use the hash to tell if two images are similar?+
Compute the Hamming distance between the two hashes (the number of differing bits). The smaller the distance, the more similar — generally under 10-12 bits means highly similar.
Is my image uploaded anywhere?+
No. All computation happens locally in your browser — your image never leaves your device.

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Image Perceptual Hash (pHash) — free online perceptual hash, phash, image hash, image fingerprint, similar images, image hash online. No signup required. Works in your browser.