hiberfil.sys: Delete the large file or use it to optimize the hibernation mode in Windows (2025)

The hiberfil.sys is one of these very large Windows system files. Often several gigabytes in size, they usually become noticeable at some point like this:

The Windows PC is running slower than usual or the hard disk space is suddenly running out.

Or both.

And then you discover this hidden file in the root directory of Windows (usually drive "C", see image).

The hiberfil.sys is the so-called hibernation file, which is often huge in Windows 10/11/7 and plays a central role in the hibernation mode of your PC.

Their name hiberfil is derived from "hibernate".

In Windows versions such as Windows 11, 10, 8 and 7, it saves the current status of your PC, including all open programs and documents.

It allows your Windows computer to boot up again faster from "sleep mode" and pick up right where you left off in no time at all.

Without this file, hibernation could not work.

But why is the size of the hiberfil.sys file sometimes gigantic?

Simple: It must be able to hold the entire contents of your working memory.

This means: The more RAM your PC uses, the larger the file will be.

However, unlike the Windows swap file, it only saves the memory contents for waking up quickly from the standby "sleep" state.

Are you wondering whether deleting hiberfil.sys is a good idea? Because the file is very large and you want to speed up your Microsoft operating system or free up disk space?

We show you when it makes sense to remove the hibernation file and how to do it.

Yes, you can delete the hiberfil.sys, but there are a few things to keep in mind.

In the various Windows versions, such as Windows 10, 8 and 7, it is responsible for hibernation.

If you don't use this function, you can delete the file and free up storage space - this tip is even given by Microsoft itself.

But beware: standby hibernation mode no longer works without it.

The middle way: Would you prefer to reduce them instead of deleting them? Then skip to the section below...

These 3 steps will show you how to securely delete hiberfil.sys in Windows 11 / 10 / 7 / XP:

Voilà, the hiberfil.sys is deleted, your hibernation mode is deactivated and your hard disk space is happy.

You will no longer find the deleted file in Explorer, see the image gallery below (only pagefile.sys and swapfile.sys are still there).

The advantage: If you deactivate hiberfil.sys, you will gain back memory space, as this file can often be several gigabytes in size.

The disadvantage? The standby mode of your Windows PC will no longer be available.

This means that you have to shut down your computer completely instead of quickly putting it into sleep mode and continuing to work seamlessly later.

So it will most likely take longer to start your PC without the hibernation file.

If you want to use hibernation on your PC again, no problem!

We'll show you how to reactivate it so that you can enjoy the benefits of a quick start and seamless continuation of work.

Activating or reactivating sleep mode is just as easy as deactivating it:

This activates the hibernation mode and the hiberfil.sys is required again and created automatically.

Reducing the size of hiberfil.sys is a frequent request from users - to save storage space without having to do without important functions such as hibernation.

The good news: Microsoft has expanded the functions and from Windows 10 you can reduce the hiberfil.sys automatically or user-defined.

We show you how to effectively save hard disk space and reduce the size of the hibernation file in Windows 11 and Windows 10 without completely giving up your standby mode.

In Windows 10, you can automatically reduce the size of hiberfil.sys using the powercfg command.

This is done via a special command in the command prompt:

After the input, a text appears with confirmation of the respective size - in my case:

The size of the quiescent state file was set to 1717874688 bytes.

This automatically reduces the size of hiberfil.sys according to system specifications, whereby the functionality of the idle state is largely retained.

But limited:

Shrinking the file may make hibernation a little slower, as less data can be saved in advance.

It is a compromise between storage space and speed.

You want to customize the hiberfil.sys and set it to a size of your choice?

To do this, open the command prompt again with administrator rights and enter the following command:

Powercfg /h /size nn

Replace the variable nn with a value between the minimum value 40 and maximum value 100.

With this command you activate the hibernation mode and specify the size of the hibernation file as a percentage of the installed memory.

Example: Here I have set my hibernation file to 80 percent:

Tip: Do not choose a number that is too small, otherwise the current memory content can no longer be inserted into the reduced hiberfil.sys.

Moving the hiberfil.sys to another drive is unfortunately not so easy.

Windows deliberately stores this file on the system drive, as it is of central importance for hibernation.

An attempt to move them could lead to system instabilities or even loss of the idle state function.

We therefore advise against moving this file.

If you still want to try to free up space on your system drive, we recommend other methods: deleting unnecessary files or minimizing hiberfil.sys as described in the previous sections.

In Windows 10 and 11, Microsoft has optimized the handling of the hibernation file.

These newer versions offer improved setting options, such as quickly reducing the file size for hibernation via the command prompt.

Windows 11 and 10 are also more efficient in their use of disk space, which means that hiberfil.sys takes up less space on your hard drive.

In older Windows versions, their management was less flexible.

Windows 8, Windows 7, Windows XP and Vista, for example, did not have the same command line options for optimizing the hiberfil.sys as Windows 10 and 11 - shrinking was not yet possible.

And way back in Windows 2000 and ME, hibernation was a newer feature and therefore not managed as efficiently as in later versions.