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JAR to RAR Converter

Convert JAR to RAR online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

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How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is a JAR file?

The JAR (Java Archive) file format is a platform-independent package file format based on the ZIP standard, originally developed by Sun Microsystems (now Oracle Corporation) to aggregate multiple Java class files, associated metadata, and resources into a single distribution unit. It utilizes the DEFLATE compression algorithm to reduce file size and necessitates a manifest file, typically located at META-INF/MANIFEST.MF, which specifies the application entry point (Main-Class attribute) and classpath dependencies. The format is integral to the Java Platform, allowing the Java Runtime Environment (JRE) to deploy applications and libraries efficiently by reducing HTTP requests during network transfer.

How to open a JAR file

To execute a JAR file as a standalone application, the host system requires the installation of a Java Runtime Environment (JRE) or Java Development Kit (JDK); users typically run the file via the command line interface using java -jar or through configured OS file associations. For static inspection or extraction of the archive's contents without execution, users can utilize standard file compression utilities such as 7-Zip, WinRAR, or the unzip command on Unix-based systems, as the JAR format complies with standard ZIP file specifications.

JAR Technical Info

Full Name
Java Archive
Developed By
Sun Microsystems (Oracle Corporation)
Initial Release
1997
MIME Type
application/java-archive

What is a RAR file?

RAR (Roshal Archive) is a proprietary archive file format developed by Eugene Roshal that supports data compression, error recovery, and file spanning. It utilizes a variation of the LZSS algorithm with a sliding window size of up to 4 MB (in RAR4) or 1 GB (in RAR5), combined with Huffman coding. Key technical features include support for AES-256 encryption, BLAKE2sp hash algorithms for file integrity, and specialized recovery records that allow for the reconstruction of damaged data. The format structure supports solid archiving, where multiple files are treated as a single continuous data stream to improve compression ratios.

How to open a RAR file

Due to the proprietary nature of the RAR licensing, creating RAR files requires licensed software (WinRAR), though extraction is supported by various free tools. Windows users typically use WinRAR or 7-Zip to extract contents. macOS users can utilize The Unarchiver or Keka. On Linux, the non-free unrar package or the open-source 7z (p7zip-full) package provides extraction capabilities via the command line.

RAR Technical Info

Full Name
Roshal Archive
Developed By
Eugene Roshal
Initial Release
1993
MIME Type
application/vnd.rar

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Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert JAR to RAR in seconds

Every JAR to RAR conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert JAR to RAR via API

Automate JAR to RAR conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "jar-to-rar",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "rar"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.jar

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.