How to use Duplicate File Finder
Add files from the sets you want to compare, then read the numbered groups in the result table. Duplicate File Finder reads each file's byte size and SHA-256 hash. Files with matching size and hash share a group. The report lists file names, sizes, hashes, status, and recoverable space, while leaving the selected files unchanged.
How to find duplicate files
- Drop files into Drop files here to compare, or select browse files to choose multiple files.
- Wait while each file is read and hashed. The drop area accepts Any file type.
- Read the summary cards and table after processing finishes.
- Select Add more files to add another batch, or select Clear all to remove the current report.
What counts as an exact duplicate file
Two files enter the same duplicate group only when their byte sizes and SHA-256 hashes both match. File names do not affect grouping, so differently named copies can share a group. A file without a matching size-and-hash pair stays unique.
Input: a.txt (12 KB), b.txt (12 KB)
Output: Group 1, duplicate, 12 KB recoverableRecoverable space counts the copies beyond one file in each group. Duplicate files counts every file in duplicate groups, including the copy kept in the calculation.
The summary cards are Files compared, Total size, Duplicate groups, Duplicate files, and Recoverable space. The table columns are Group, File name, Size, SHA-256, and Status.
How to filter and export duplicate file results
Type a filename into Search files by name… to narrow the visible rows. Select Duplicates only or Unique only to filter by status. Reset filters clears the search and both status filters. When both status filters are active, the result table is empty.
The count follows X of Y files. Select CSV or JSON to export every processed file, including rows hidden by the current search or filters. The exported fields are name, size, SHA-256, group, and duplicate status.
Duplicate file finder limits and failed reads
The page does not set a numeric maximum for file count, individual file size, or total data size. Each file is loaded into an in-memory ArrayBuffer, so available device or browser memory limits the batch you can process. Files are hashed one at a time. If a read or hash fails, the page keeps that batch out of the report and shows an error beginning with Could not read a file:.
Where to use a duplicate file finder
For copied assets in two project folders, select files from both sets and inspect the numbered groups before choosing which copies to keep.
For backup or export files, add each batch with Add more files, then check Recoverable space before making a separate cleanup decision.
When another person needs the comparison record, export CSV or JSON. The file names, sizes, hashes, groups, and statuses are included.
Choose the right file analysis tool
Duplicate File Finder is part of File Management Analyze Tools. Choose File Age & Path-Length Analyzer for file age or path length, File Type Detector for a format identified from its signature, or Folder Size Analyzer for folder totals, largest items, or a storage breakdown.
Frequently asked questions
How does a duplicate file finder identify exact duplicates?
It groups files only when their byte sizes and SHA-256 hashes both match. The file names can differ.
Can I find duplicate files with different names?
Yes. Different names can appear in one group when the files have the same size and SHA-256 hash.
Can I remove duplicate files with this tool?
This tool leaves the selected files unchanged. It reports groups and recoverable space for a separate cleanup decision.
Does Duplicate File Finder upload files?
Files stay in the browser while the File API reads them and the Web Crypto API hashes them. The page makes no request that sends the selected file content to a server.