Why compress files

The middle image is the result of saving this as a JPEG at 50 percent quality. And the rightmost image shows the original image saved instead as a 10 percent quality JPEG. At a quick glance, the middle image doesn't look too bad. You can only notice the artifacts around the edges of the boxes if you zoom in. Of course, the rightmost image immediately looks terrible. Lossless compression is a way of reducing file size so that you can perfectly reconstruct the original file.

Contrary to lossy compression, it doesn't throw any information out. Instead, lossless compression essentially works by removing redundancy. Let's take a basic example to show what this means. Below is a stack of 10 bricks: two blue, five yellow, and three red.

This stack is a simple way to illustrate those blocks, but there's another way to do so. Instead of showing all 10 blocks, we can remove all but one of each color. Then, if we use numbers to show how many bricks of each color there were, we've represented the exact same bit of information using far fewer bricks. Instead of 10 bricks, we now only need three.

This is a simple illustration of how lossless compression is possible. It stores the same information in a more efficient way by removing redundancy. Consider an actual file, where the below string:.

This allows us to use seven characters instead of 24 to represent the same data, which is a significant saving. As we mentioned above, lossless compression is important in cases where you can't remove any of the original file.

If you've been curious as to how ZIP files work, this is the answer. When you create a ZIP file from a program executable in Windows, it uses lossless compression. The ZIP file compression is a more efficient way to store the program, but when you unzip decompress it, all the original information is present.

If you used lossy compression to compress executables, the unzipped version would be damaged and unusable. Lossless formats for video are rare, because they would take up massive amounts of space. It's really easy to open ZIP files on most devices, and it can still compress files to smaller sizes.

Select Ultra from the "Compression Level" menu. This tells 7-Zip to compress the file into the smallest possible size. The amount of compression will vary depending on the type of file you're compressing. If you don't see this option, try LZMA instead. This format is the most modern compression method available and will work on most devices. Set "Dictionary Size" to a value that is at least 10 times lower than your memory. A larger dictionary size means better compression, but the memory requirements are ten times the dictionary size.

In most cases, MB will suffice, as it provides excellent compression at a decent speed. Select the option to split the file into smaller files optional. You can leave the other remaining options set to their default settings. But if a file is particularly large, you have the option to split the file into smaller files.

For example, you could take a 12 GB folder and split it into three smaller files that could each fit onto a DVD. Use the drop-down menu below "Split to volumes, bytes" to select how big you want each split file to be. You will need all the split files to extract the files. Make sure you do not delete or lose any of the split files. Click Ok to compress the file.

This compresses the file using the settings you specified. Method 2. Download and install WinRAR. WinRAR is a free for a limited time application you can use to compress files on Windows. Click the blue WinRAR 6.

Open the WinRAR ". Click Install and follow the on-screen instructions. Nearly all files can be compressed, but some files can only be compressed by a small amount. The icon looks like a stack of books. Select an archive format. ZIP is the standard compression option and easiest to open on any system. Select Best from the "Compression Method" menu.

This method provides the highest compression ratio the smallest size file. Select a Dictionary Size. The default option will already be selected based on the archive format you selected. The larger the dictionary file, the more compressed the file can be. However, compression and decompression can take a long time and large dictionary sizes require better computer hardware. You can try a size that is 10 times lower than your memory, or stick to the default if that takes too long.

If a file is particularly large, you have the option to split the file into smaller files. Use the drop-down menu below "Split to volumes, size" to select how big you want each split file to be. Click Ok. It's in the lower right corner. This compresses your file. Method 3. Right-click the file s you want to compress. To select more than one file at a time, press and hold the Command key as you click each file. Then, right-click the highlighted files.

You can compress most files types on your Mac. The size of the compressed file will vary depending on the type of file it is—images, text files, and various documents can usually compress to much smaller files than video and audio, for example.

Click Compress. This compresses the file into a ZIP file, which also reduces its size. ZIP file extension, which is a globally-used compression format that can be opened on nearly any system without needing special software. To decompress the file, double-click it.

Method 4. Download Avidemux. To compress a large video into a smaller file, you'll need compression software that's specifically for video. Avidemux is a free option that can considerably decrease a video's size, and it's available for Windows, Mac, and Linux. Click the download link for your operating system. Open the downloaded file in your web browser or Downloads folder.

Follow the instructions to complete the installation. Launch Avidemux. You'll find it in the Windows Start menu or your Mac's Applications folder. Sure, you could send a series of multiple emails with small attachments on each, but that's both time consuming and hard to keep track of and you'll probably annoy the recipient.

By compressing your documents into one ZIP file, it will take up less space and transfer a lot faster. The recipient just needs to use a program like WinZip to extract the files and they'll have everything you sent them in one, organized folder.

Hard drives are expensive - I don't have to tell you that. Storing loads and loads of data obviously takes up tons of space, so why not get the most bang for your buck? Say you have GB of data you need to stash away on your computer, but your hard drive is only GB.

Sure it will fit, but then you're left with only 50GB which isn't much these days. You could go out and buy a larger, more expensive hard drive, transfer everything from the old one to the new one, and be good to go. You still have all of your files, ready to use when you need them, but you don't have to spend any money on more storage space.

At this point, you should have a pretty solid understanding of file compression - how it works and why it's beneficial. That's great and all, but you probably want to know how to zip and unzip files yourself, right? The following is a crash course on the process of compressing and decompressing files.

Luckily, if the files you're trying to compress are relatively small, your operating system should be able to zip them without the need of 3rd party software. A simple right click option will take care of it for you. But what if you're dealing with several gigs of data? You're going to need something with more "oomph" to take care of things. Lucky for you WinZip is a leading file compressor. So, that about sums up the basics of file compression.

It sounds impossible being able to reduce the size of a file, then put it back together in another location, but that's essentially what happens.

If you're interested in learning more, check out WinZip's website for more documentation. WinZip 26 NEW! Need to Download WinZip? Download a Free Day Trial Now! It takes just seconds to compress, stuff, or zip them. You can prevent large files from using up network resources with a compression utility such as:. Many word processing documents can be compressed to 10 percent of their original size. Current Windows and Mac operating systems include compression software for zipping large files.

In macOS, control-click any file and choose Compress from the menu options to reduce file size. The recipient expands the compressed file by double-clicking it. If the file you want to attach to an email surpasses 10 MB or so, even after compression, it's better to use a file-sending or cloud-storage service rather than attach it to an email.

Most email service providers place limits on the size of files they will send. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance.