The fastest way to shrink a 200MB file to 15MB

You can reduce a 200MB file to 15MB by compressing it with software that removes redundant data — the most common tool is WinRAR on Windows or The Unarchiver on Mac, both of which let you choose compression strength before you create the archive. A 200MB file compressed to 15MB represents roughly a 92% reduction, which is aggressive but achievable for certain file types like documents, spreadsheets, or older video formats that were not already compressed.

The actual shrinkage you get depends entirely on what is inside the file. A folder of Word documents or PDFs compresses heavily because they contain a lot of repeated patterns. A video file or image already compressed with modern codecs will barely shrink at all, because the compression is already baked in. Before you start, check what you are actually compressing — if it is already a .mp4, .jpg, or .zip file, you will not reach 15MB no matter what tool you use.

Key Takeaways

  • Compression strength is a slider you control — higher compression takes longer but produces smaller files, and you can test different settings before committing.
  • Files that are already compressed (video, modern images, audio) will not shrink much further, so check your file type first.
  • WinRAR on Windows and The Unarchiver on Mac are the standard tools; both show you the compressed size before you finish.
  • If you cannot reach 15MB through compression alone, you may need to remove content from the original file or split it across multiple archives.

Using WinRAR on Windows to compress to a target size

Open WinRAR and navigate to the 200MB file or folder you want to compress. Right-click it and select "Add to archive" — this opens the compression dialog where you control everything. In the "General" tab, give your archive a name and choose the location where it will be saved.

Click the "Compression" tab. You will see a slider labeled "Compression method" with options from "Store" (no compression) to "Best" (maximum compression). Select "Best" to get the smallest possible file. Below that, you may see an option for "Compression level" — set this to the highest number available. Click "Test" if you want WinRAR to show you the estimated final size before you commit, then click "OK" to create the archive. WinRAR will display a progress window; compression can take several minutes depending on file type and your computer speed.

When it finishes, right-click the new .rar file and select "Properties" to see the exact compressed size. If it is still larger than 15MB, you have two options: compress again with different settings (though this rarely helps much), or remove some content from the original file before compressing.

Using The Unarchiver on Mac to compress files

Mac does not include a built-in tool for creating compressed archives with strength controls, so you will need to read The Unarchiver (free from the Mac App Store) or BetterZip (paid, more powerful). The Unarchiver is simpler for basic compression.

Open The Unarchiver, then drag your 200MB file or folder into its window. The app will ask you where to save the compressed version and what format you want — choose .zip for maximum compatibility. The Unarchiver does not offer compression strength controls the way WinRAR does, so the compression level is fixed. If the resulting .zip file is still too large, you will need a more advanced tool like BetterZip, which gives you slider controls similar to WinRAR.

Understanding why some files compress more than others

A 200MB folder of text documents, spreadsheets, or PDFs will often compress to 15MB or smaller because these file types contain a lot of repetition — the same fonts, formatting, and white space appear over and over. Compression algorithms find these patterns and replace them with pointers, shrinking the file dramatically.

Video files, audio files, and modern image formats (.mp4, .jpg, .png, .webp) are already compressed using specialized codecs that remove redundancy as part of their design. Running them through a general-purpose compressor like WinRAR or The Unarchiver will barely shrink them — you might lose 5% to 10% at most. If your 200MB file is a video or image, reaching 15MB through compression alone is not realistic. Your only option is to reduce the quality or resolution of the original file before compressing.

What to do if compression alone will not reach 15MB

If you have compressed with maximum settings and the file is still larger than 15MB, the content itself is too large for that target. You have three realistic options: split the archive across multiple files, remove content from the original, or accept a larger file size.

To split an archive, use WinRAR's "Split to volumes" feature in the compression dialog — you can set a maximum size for each part (for example, 10MB per file), and WinRAR will create multiple .rar files that must be extracted together. This works if you need to send the file in chunks or store it on a device with size limits. The Unarchiver on Mac does not have this feature, so you would need to manually divide the original content into separate folders and compress each one.

If the file is a video or image, you can reduce its quality or resolution before compressing. Open it in the appropriate editor (video editing software for .mp4, image editor for .jpg), export it at lower quality settings, then compress the smaller result. This is the only way to reach 15MB if the original is already a compressed format.

Testing compression before you commit

Both WinRAR and The Unarchiver show you the compressed size before the operation finishes. In WinRAR, click "Test" in the compression dialog to see an estimate. In The Unarchiver, the app shows the result when ready after compression completes, so you can delete it and try again with different settings if needed.

If you are working with a very large file and compression is taking a long time, you can pause the operation in WinRAR by clicking the pause button in the progress window. This lets you check the current size and decide whether to continue or cancel and try a different approach.

Frequently Asked Questions

Can I compress a file that is already a .zip or .rar?

You can, but it will not shrink much — the file is already compressed. Compressing it again is called "double compression" and rarely reduces size by more than 1% to 3%. If your original file is already a .zip or .rar, the content inside is what matters. Extract it first, then check what you are actually compressing.

Will compression damage my files or make them unreadable?

No. Compression is lossless — when you extract the archive, the files inside are identical to the originals. The only exception is if you use lossy compression (reducing video or image quality), which permanently changes the original content. Standard archive compression does not do this.

How long does it take to compress a 200MB file?

It depends on your computer and the file type. Text and documents usually compress in under a minute. Video or large image files can take 5 to 15 minutes with maximum compression settings. You can watch the progress window to see how much time remains.

What if I need to send the 15MB file to someone — will they be able to open it?

Yes, as long as you use a standard format like .zip. Almost every computer can extract .zip files without additional software. If you use .rar, the recipient will need WinRAR or another .rar reader installed, which is less common. Stick with .zip for the widest compatibility.

Can I compress a file directly without creating an archive?

Not in the traditional sense. Compression tools create archives (.zip, .rar) as containers. You cannot compress a single file "in place" — you always end up with a separate compressed copy. If you want to replace the original with a smaller version, you will need to delete the original after confirming the archive works.