Offline Installer [verified] | Telerik Justdecompile

Telerik JustDecompile was a popular free .NET decompiler, it has been officially retired by Telerik. Because the product is no longer actively maintained, finding a direct "offline installer" from the official site now involves specific workarounds or looking at its successor. Status of the Offline Installer

The official web installer often required an active internet connection to download components during setup. However, Telerik previously offered two primary ways to obtain a standalone version for offline use: ZIP File Distribution : Telerik provided a ZIP version of JustDecompile

that required no installation. This is the most "offline-friendly" version, as you can simply extract it to a USB drive or a local server. Account MSI Download : For users with a Telerik account, a standalone MSI installer was typically available on the Downloads page Key Features for Offline Use

Even without a constant connection, JustDecompile offered robust features for assembly browsing: One-Click Framework Loading

: Quickly load core assemblies for .NET 2 through 4.5, WinRT, and Silverlight. Project Recovery

: Use the "Create Project" feature to export decompiled assemblies into a Visual Studio project. High Performance

: It was marketed as being up to 10 times faster than competing decompilers. Current Alternatives

Since Telerik has retired JustDecompile, they officially recommend these active, free alternatives for offline .NET decompilation:

: A powerful tool from JetBrains that can act as a local symbol server. : A widely used open-source decompiler. CodemerxDecompile

: JustDecompile’s engine was open-sourced and has been continued by some communities under names like CodemerxDecompile or another modern alternative instead?

Download the Full Ultimate package Offline in UI for .NET MAUI 10 Nov 2023 —

Telerik JustDecompile is a tool that is no longer officially supported by Progress Telerik. While the official product page has been retired, you can still find ways to use it or its modern successor for offline needs. Telerik.com Current Status & Download Options

As of 2026, the original Telerik JustDecompile has reached its end-of-life. Telerik.com Official Offline Installer: Historically, Telerik provided an offline installer in formats via their JustDecompile FAQ page telerik justdecompile offline installer

. However, new downloads are officially discontinued on the main product site. The ZIP "No-Install" Method: A popular offline alternative was the ZIP file distribution

, which allowed users to run the tool from a USB drive or server without a formal installation process. Modern Successor (CodemerxDecompile):

Since the original engine was open-sourced (Apache 2.0 license), it was forked into CodemerxDecompile

. This version continues to be maintained and offers installers for Windows, Mac, and Linux. Telerik.com How to Install Offline (If you have the files) If you already possess the files from your Telerik account: MSI Installation:

Double-click the installer and follow the wizard. It may require an administrator account for configuration. ZIP Extraction: Simply extract the contents to a local folder. You can add %PROGRAMFILES(X86)%\Telerik\JustDecompile\Libraries Path environment variable to enable command-line usage. Connectivity Warning:

Be aware that some older Telerik installers might attempt to download the latest version of .NET Framework if it is not already present on the machine. Telerik.com Key Features for Offline Use Command Line Support:

JustDecompile.exe /out:[OutputDirectory] /target:[PathAndAssemblyName] to decompile assemblies without using the GUI. Project Export:

You can create full Visual Studio projects from decompiled assemblies by right-clicking them in the tree view. Open Source Engine:

The core decompilation engine remains available on GitHub for those who want to build their own local version of the tool. Telerik.com Alternatives for Offline Decompilation

If you cannot find the original Telerik installer, consider these widely used alternatives:

Powerful debugger and assembly editor (No longer actively updated, but popular). The standard open-source .NET decompiler. A free standalone tool from JetBrains. JustDecompile FAQ - Telerik.com

Can decompiled code be directly exported from JustDecompile? Yes. We have "Create Project" from decompiled assembly functionality. Telerik.com Telerik JustDecompile was a popular free

Installing without internet connection in Fiddler | Telerik Forums

If you are looking for a reliable way to analyze .NET assemblies without a constant internet connection, the Telerik JustDecompile offline installer

is the essential tool for your kit. While many modern installers rely on "web stubs" that download files during the setup process, having the full standalone executable ensures you can install the decompiler on secure workstations or remote environments. Why Use the JustDecompile Offline Installer? Zero Dependencies

: Install the full suite on machines with restricted internet access or behind strict corporate firewalls. Speed & Reliability

: Avoid "download failed" errors mid-installation. Once you have the MSI or EXE, the setup is near-instant. Version Control

: Keep a specific version of the tool archived so your entire team is debugging and decompiling on the exact same build. Portability

: Easily move the installer to different dev environments via USB or internal networks without re-downloading 100+ MBs. Key Features of JustDecompile

JustDecompile remains one of the fastest free decompilers on the market, offering features that rival paid alternatives: High-Performance Decompilation

: Quickly turns .NET assemblies (EXE and DLL) back into readable C#, VB.NET, or IL code. Extensible Plugin System : Enhance your workflow with community plugins like the assembly editor or deobfuscators. Visual Studio Integration

: Seamlessly jump from your project code into decompiled third-party libraries. Create Visual Studio Projects : It can reconstruct an entire from a compiled assembly, saving hours of manual recovery. How to Get It To find the offline version, log into your Telerik/Progress account

and navigate to the "Downloads" section. Look for the "Standalone Installer" or "Offline Installer" link rather than the default "Control Panel" web setup. If you're using a package manager like Chocolatey , you can often trigger an offline-friendly install using choco install justdecompile

Telerik JustDecompile is a high-performance, free tool developed by Progress Telerik for browsing and decompiling .NET assemblies. While many modern developer tools rely on online installers or NuGet feeds, the offline installer remains a popular choice for developers working in air-gapped environments or those who prefer a single, portable executable for quick deployment. Review: Telerik JustDecompile (Offline Edition) they officially recommend these active

Ease of InstallationThe offline installer is straightforward, allowing you to bypass the need for a constant internet connection during the setup process. This is particularly useful for enterprise environments with strict firewall rules. However, users should note that as of 2025, Telerik has transitioned many products to a new licensing mechanism that may still require a one-time activation or specific DLL references. Key Features & Performance

Versatile Decompilation: Easily converts compiled .dll and .exe files back into readable C#, VB, or IL code.

Integrated Search: Includes a robust symbol-browsing feature that helps you navigate complex codebases quickly.

Extensibility: Supports plugins (like the Assembly Editor or Reflexil), though these may require manual configuration when using the offline version.

Speed: Known for being incredibly fast, it handles large assemblies without the lag often seen in browser-based tools. Pros

Completely Free: Unlike many Telerik UI suites, JustDecompile is a free utility.

Clean UI: It maintains the polished, professional interface Telerik is known for.

Reliable Support: Even as a free tool, it benefits from the extensive documentation and community resources provided by Progress Telerik. Cons

Stagnant Updates: Some users have noted that while the tool is reliable, feature updates are less frequent than Telerik’s paid UI components.

Licensing Friction: Recent changes to the Telerik licensing runtime (Q1 2025) have introduced occasional "Could not load file or assembly" errors for some users, which may require manual troubleshooting. Verdict

If you need a reliable, professional-grade .NET decompiler that works without an internet connection, the Telerik JustDecompile offline installer is an excellent choice. It remains one of the best free alternatives to tools like dotPeek, especially for users who already operate within the Telerik ecosystem. JustDecompile FAQ - Telerik.com

Telerik JustDecompile is a professional-grade, free tool designed to decompile compiled .NET assemblies (DLLs and EXEs) into readable C#, VB.NET, or MSIL code. While it has been a staple in the .NET ecosystem for years, it was officially retired by Progress Telerik. New official downloads are no longer available on the main Telerik product page, though users who previously downloaded it can continue to use it. Core Features JustDecompile FAQ - Telerik

Common Use Cases for JustDecompile Offline

For Windows (GUI)

Disable SmartScreen temporarily (optional): Right-click the installer → Properties → Check "Unblock" (if downloaded from internet).
Run as Administrator: Right-click the .exe → "Run as administrator".
Accept License: You’ll see the standard Telerik EULA.
Select Features:
- Core Decompiler (required)
- Visual Studio Extension (optional – requires VS 2017–2022)
- Shell Extension (right-click .dll files in Explorer)
Choose Install Path (default: C:\Program Files\Telerik\JustDecompile\).
Click Install – This will take 30–60 seconds. No network activity.
Launch – Find JustDecompile in your Start Menu.

Important Prerequisites

Before running JustDecompile on your offline machine, ensure the machine has the correct prerequisites installed. If the app crashes on startup, you are likely missing one of these:

.NET Framework 4.8: JustDecompile requires the full .NET Framework 4.8 (it does not run on .NET Core/.NET 5+ alone).
Visual Studio 2010 Tools for Office Runtime: Some older versions of JustDecompile relied on specific Office runtime components.