You can reduce a 200MB file to 15MB by compressing it, but the result depends on what's inside

A 200MB file compressed to 15MB means removing about 92% of its size. That's possible, but only if the file contains data that compresses well — text, documents, or images with repeated patterns. If it's already a video or photo in a compressed format like MP4 or JPG, you won't get anywhere near that ratio. The method you use matters too. You might compress the file itself, convert it to a different format, or split it across multiple smaller files.

Before you start, open the file's properties to confirm what you're working with. On Windows, right-click the file, select Properties, and look at the file type. On Mac, right-click and choose Get Info. The file extension (the letters after the dot) tells you what kind of data it holds, and that determines which shrinking method will actually work.

Key Takeaways

  • Text files, PDFs, and uncompressed images shrink dramatically with standard compression tools; video and audio files that are already compressed will barely shrink at all.
  • Windows has a built-in compression tool (right-click, Send to, Compressed folder); Mac users can use Archive Utility or third-party tools like Keka.
  • If compression alone won't get you to 15MB, you may need to convert the file to a lower-quality format or split it into multiple pieces.
  • Test the compressed file to make sure it still opens and works the way you need it to before you delete the original.

Compress the file using Windows built-in tools

Windows includes a compression feature that works on most file types. Right-click the 200MB file, hover over Send to, and click Compressed (zipped) folder. Windows will create a new file with a .zip extension in the same location. This usually takes a few seconds to a few minutes depending on file size and your computer's speed.

Once the compressed file appears, right-click it and select Properties to see how much space it actually saved. If it's already down to 15MB or smaller, you're done — you can delete the original 200MB file and keep the .zip version. If it's still larger than 15MB, the file probably contains data that doesn't compress well, and you'll need to try a different approach.

Use third-party compression software for better results

If Windows compression doesn't shrink the file enough, tools like 7-Zip or WinRAR often do better. 7-Zip is free and works on Windows. Download it from the 7-zip.org website, install it, then right-click your 200MB file, select 7-Zip, and choose Add to archive. In the dialog that opens, you can choose compression level — set it to Ultra or Maximum for the smallest possible file.

WinRAR is paid software but offers a free trial. It works similarly: right-click the file, select Add to archive, and adjust the compression settings. Both tools let you see the estimated compressed size before you commit, so you can tell whether you'll hit 15MB before waiting for the compression to finish.

On Mac, the built-in Archive Utility compresses files when you right-click and select Compress. If that doesn't shrink it enough, download Keka (free) or The Unarchiver (free) from the App Store, which offer more compression options.

Convert the file to a smaller format if compression fails

If the file is a video, audio file, or image and compression alone won't work, you may need to convert it to a format that takes up less space. For video, tools like HandBrake (free, works on Windows and Mac) let you re-encode the file at a lower resolution or bitrate. Open HandBrake, load your 200MB video, and select a preset like Fast 720p or Fast 480p. This will reduce quality but also file size dramatically.

For audio files, Audacity (free) lets you export at a lower bitrate. Open the file, go to File, Export, and choose MP3 or OGG format with a lower bitrate setting — 128 kbps instead of 320 kbps, for example. For images, batch conversion tools like ImageMagick or online converters can reduce resolution or quality across multiple files at once.

Be aware that converting always loses some quality. Test the converted file to make sure it still looks or sounds acceptable before you delete the original.

Split the file into smaller pieces if you need to keep the original format

If you need to keep the file in its current format and compression won't work, you can split it into multiple smaller files. 7-Zip and WinRAR both have a split feature. In 7-Zip, right-click the file, select 7-Zip, Add to archive, then in the dialog look for the Split to volumes option. Enter 15 (for 15MB) and 7-Zip will create multiple .7z files that add up to the original size but each one is 15MB or smaller.

When you need to use the file again, extract all the pieces together — the software will automatically reassemble them. This method doesn't actually reduce the total size, but it lets you move or store the file in chunks if that's what you need.

Check the compressed file before deleting the original

After compression or conversion, always open the new file to make sure it works. If it's a document, open it in the program you normally use. If it's a video or audio file, play a section of it. If it's an archive (a .zip or .7z file), extract it to a test folder and check that the contents are there and readable.

Only after you've confirmed the new file works should you delete the original 200MB version. If something went wrong during compression, you'll still have the original to try again with a different method.

Frequently Asked Questions

Why won't my file compress below a certain size?

Files that are already compressed — like MP4 videos, JPG images, or MP3 audio — contain very little redundant data for compression tools to remove. Compressing them again usually saves only 5 to 10% at most. If you need it smaller, you have to convert it to a lower-quality version of the same format.

Will compressing a file damage it?

No. Compression removes nothing permanently — it just reorganizes the data so it takes up less space. When you extract the file, it returns to its original state. Always test the extracted file to confirm, but damage from compression itself doesn't happen.

What's the difference between .zip and .7z files?

.zip is more widely supported — almost every computer can open it without extra software. .7z compresses more aggressively and creates smaller files, but requires 7-Zip or similar software to open. For sharing, .zip is usually safer; for personal storage, .7z saves more space.

Can I compress a file that's already in a .zip?

You can, but it usually won't help. Compressing a .zip file again rarely shrinks it further because the data inside is already compressed. Extract it first, then try a different approach like format conversion.

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

It depends on your computer and the compression level. Basic compression takes a few seconds to a minute. Maximum or Ultra compression can take 5 to 15 minutes. Faster computers finish quicker, and older machines take longer.