Duplicate File Finder

ReadyHow to use

Find byte-identical files in a folder by SHA-256, not by name.

FilesBrowser workspace

Free to use. No account, no daily limit, and no backend processing for tool input.

Choose a folder

Pick a folder — contents are hashed locally and never uploaded

Ignore empty filesEvery zero-byte file is byte-identical to every other, so they would otherwise form one large and useless group.

100% in your browser — files never leave your device.

Tip: use samples, upload, copy, download, and send-to actions inside the workspace where available.

What is Duplicate File Finder?

Duplicate File Finder is a free, browser-based tool that helps you understand a dataset at a glance. Find byte-identical files in a folder by SHA-256, not by name. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.

How to use Duplicate File Finder

1Paste your data or drop a file (CSV or JSON).
2Read the generated summary — types, counts, distributions, and any issues found.
3Export the report, or send the data to another tool to act on the findings.

Features

Per-column types, nulls, uniques, and stats
Spot data-quality issues fast
100% client-side — no upload, fully private
Free with no account, no watermark, and no daily limit
Works on large inputs, limited only by your device's memory
Load a sample, then copy, download, or share your result

Common uses

Quick one-off analyzer jobs without opening a heavy app
Preparing data before importing it elsewhere
Sharing a reproducible result with a teammate via a link

Used by

Developers
Security analysts
Support teams
QA engineers
Analysts
Researchers

Common errors

A summary is treated as proof that the dataset is clean.
Outliers are removed automatically without checking whether they are real events.
Column types are trusted without reviewing mixed or sparse fields.
Duplicate or missing-value issues are ignored before visualization.

How it works

1Profiles the data input.
2Computes counts, inferred types, summaries, and warnings where supported.
3Turns findings into a practical next step.

Recommended workflow

1
Prepare the input
Profile the data first so missing values, types, duplicates, and outliers are visible before you edit it.
2
Run Duplicate File Finder
Review the preview, copy or download the result, and keep everything local in your browser.
3
Next recommended tool
Folder Tree Generator: Turn a folder into an ASCII, Unicode, or Markdown tree with sizes.
Open tool
4
Then continue with
File Metadata Viewer: Inspect true type, MIME, entropy, dimensions and SHA-256 of any file.
Open tool
5
Then continue with
Batch File Renamer: Rename many files at once with patterns, counters, and collision checks.
Open tool

Frequently asked questions

How do I use Duplicate File Finder?: Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Find byte-identical files in a folder by SHA-256, not by name.
Is my data uploaded or stored anywhere?: No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.
Is Duplicate File Finder free?: Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.
What's the maximum file size?: There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.
Do I need to install anything?: No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.

What is Duplicate File Finder?

How to use Duplicate File Finder

Features

Common uses

Used by

Common errors

How it works

Recommended workflow

Prepare the input

Run Duplicate File Finder

Next recommended tool

Then continue with

Then continue with

Frequently asked questions

What is Duplicate File Finder?

How to use Duplicate File Finder

Features

Common uses

Used by

Common errors

How it works

Recommended workflow

Prepare the input

Run Duplicate File Finder

Next recommended tool

Then continue with

Then continue with

Frequently asked questions