Compare Files Online

The only online tool that decompiles two files and compares the actual source code — Java, C#, or Python — side by side. No installation required.

1st File

Drop 1st file here
Choose file

2nd File

Drop 2nd file here
Choose file

Supported Formats

JAR

Java archives

APK

Android apps

WAR

Web archives

EXE

.NET executables

DLL

.NET libraries

DEX

Dalvik bytecode

How It Works

1

Upload

Drop old and new versions of your file into the upload areas.

2

Decompile

Both files are decompiled to source code using format-specific decompilers.

3

Diff

View a unified diff of every changed, added, or removed source file.

Why Compare Decompiled Source?

Most diff tools compare text files or show binary-level differences like file sizes and checksums. This tool goes further: it decompiles both files into readable source code and then compares the actual logic. You see exactly which classes changed, which methods were added, and which lines of code differ.

This is useful for auditing library upgrades, reviewing APK updates for suspicious changes, comparing different builds of the same application, or recovering understanding of what changed between two releases when you don't have the original source code.

Source-Level Diff vs. Binary Diff

Traditional file comparison tools like JarComp, pkgdiff, or generic online diff checkers only show you structural differences: which files were added, removed, or changed in size. They cannot tell you what changed in the code itself because they treat files as opaque binary blobs.

This tool takes a fundamentally different approach. It decompiles each file to its original source language — Java for JARs and APKs, C# for EXEs and DLLs — and then generates a unified diff of the resulting source trees. The result is identical to what you would see running diff on two source repositories: every changed line, every added method, every removed class.

Frequently Asked Questions

How does the online file diff tool work?

Upload two versions of the same file. The tool decompiles both files into source code using format-specific decompilers, then generates a unified diff showing every changed line, added file, and removed file.

What file formats can I compare?

You can compare JAR, WAR, APK, DEX, EXE, DLL, PYC, Lua, and other formats supported by decompiler.com. Each file is decompiled to its source language before comparison.

How is this different from other diff tools?

Most online diff tools compare text or show binary-level differences like file sizes and checksums. This tool actually decompiles both files into readable source code and then diffs the source. You see what changed in the actual code, not just that something changed.

Is my file safe?

Yes. Uploaded files are stored temporarily for decompilation and comparison, then automatically deleted. Files are never shared with third parties.

Is it free?

Yes, the tool is completely free to use. There is no registration required and no file count limit.

How long does the comparison take?

Most files are decompiled and compared in under 30 seconds. Large files may take longer, but you can start browsing partial results while decompilation continues in the background.