File names: best practices for naming files

By teamnext Editorial Team

In today’s digital environment, every larger company creates, edits, and shares countless files. Well designed file names improve findability and make information sharing easier. A consistent naming system can contribute to productivity more than expected.

Before looking at best practices, it helps to consider what it means to work without a system.

Almost every PC user has spent time searching for poorly named files in a digital haystack. If the file is not found within a few minutes, the process quickly becomes frustrating.

Poor file names are especially problematic when the following are missing as well:

Metadata such as keywords or descriptions
A meaningful folder structure

This situation is not only the least favorable, but also common. Users who do not invest effort in naming files typically also do not create suitable metadata or folder structures.

This is common among private users. In companies, there are often attempts at a filing system, although there are also many cases of disorder.

Systematic file naming is a first step toward improved findability. This article focuses deliberately on this first step. It is surprising how much can be achieved with order and consistency.

The simplest system is not the worst

There are use cases where a simple sequential number as a file name makes sense, for example in photo agencies or similar digital archives. In that case, leading zeros are important. Otherwise, sorting errors can occur, such as:

1.jpg
10.jpg
2.jpg
3.jpg

The number of leading zeros should match a realistic maximum. For a larger photo agency that markets millions of stock photos, it could look like this:

00000001.jpg
00000002.jpg
00000003.jpg
…
99999999.jpg

With 8 digits, this allows for 100,000,000 minus 1 possible image numbers, which is more than sufficient in many scenarios.

Note: In archives and libraries, the principle of sequential numbering is also known as Numerus Currens.

Using the date as part of the file name

Using time related aspects such as the creation date of a file or the capture date of a photo as an organizing principle is useful and widely adopted. There are key points to consider:

For chronological sorting, the date must be placed at the beginning of the file name.
The format should be sortable, for example YYYYMMDD or YYYY-MM-DD.
At least one additional attribute should be added for differentiation.

Following these principles, valid file names could look like this:

20240403_001.jpg
20240403_999.jpg
20241001_010.jpg

The date is used as a prefix in sortable form, and the suffix is a running number.

Avoid special characters and spaces

Some special characters cannot be used in file names because operating systems do not allow them. On Windows, this includes:

On macOS, / and : are not allowed or can cause issues. On Linux systems, it is typically only /.

To enable error free file exchange across operating systems, it is recommended to follow the Windows list of invalid characters.

On Windows, some file names consisting of 3 to 4 characters are also reserved for the system. Examples include nul, con, or com0. These names cannot be created regardless of the file extension. For details, see the Windows naming conventions.

Ensure web compatibility

If files are used in a cloud environment, shared via links, or embedded in websites, file names should be chosen so that characters can be used directly in a URL. Otherwise, URLs become hard to read and difficult to remember, as this example shows:

File name: neue Maßstäbe.pdf
URL encoded: neue%20Ma%C3%9Fst%C3%A4be.pdf

If spaces are replaced with underscores or hyphens, umlauts with ae, oe, or ue, and Eszett with ss, the result is more readable:

neue-Massstaebe.pdf

A combination of underscores and hyphens can be useful to replace spaces because it improves readability, as long as it is applied consistently.

Uppercase and lowercase

Depending on the operating system and configuration, file names may or may not be case sensitive. On Windows, file names are not case sensitive. On most Linux distributions, they are. On macOS, both are possible, although the default is typically case insensitive.

On Windows, a single path cannot contain two files that differ only by capitalization. Searching for test.jpg is equivalent to searching for Test.jpg. On Ubuntu Linux, a search can differentiate between test.jpg and Test.jpg.

What does this mean for file naming?

It becomes relevant when URLs are involved. The path segment of a URL behaves case sensitively. The following URLs could point to three different pages:

For Linux oriented users, this may be a logical consequence. Windows users often find it confusing. In any case, having several almost identical URLs is undesirable.

Does this mean file names should always be lowercase? That may be demanding, but it standardizes web based file exchange. If web compatibility is a priority, file names should be written in lowercase:

grundsaetze-fuer-dateinamen.html

The most common file names

The most common file names often start with program defaults, for example Dok1.docx, Mappe1.xlsx, or Scan1.pdf.

Then there are file names that were entered manually, but reveal little beyond a status, for example Text_neu.docx, Entwurf_v1.docx, or Logo_final_final.psd.

The worst names often result from fast naming under time pressure:

Very short names such as a.jpg
Generic placeholders such as temp.txt
Cryptic names such as asdf.docx

How much content should be included

By now, it should be clear what to avoid. The next step is defining what good file names look like.

Including a version indicator can be helpful. More important is including content related cues. When searching later, people typically look for terms related to content, purpose, or context.

Content references should be short, precise, and unambiguous. Using clear abbreviations can help. Longer descriptions or keyword lists do not belong in the file name. They belong in metadata containers.

Is there a DIN standard for file names

Yes. DIN 5008:2020-03 dedicates section 25.3 to file naming. The key rules have already been covered here, but it is useful to restate the core points:

File names consist of two to three parts, for example date, context, content keyword.
A separator should be used between the parts.
Dates should be numeric in the order year, month, day.
For sorting, the order of elements can be changed.
Spaces and special characters such as umlauts should be avoided in file names.

The most important rule is:

File naming should be consistent within an organization.

Consistency is key

File naming conventions and schemas should be defined across the organization. This also applies to the content related parts of a file name. If, for example, a document relates to an annual general meeting, a consistent term and spelling should be used. In practice, it often looks like this, with three years and three different schemas:

Einladung JHV 2022.pdf
Jahreshauptversammlung-2023-Einladung.pdf
Einladung_Hauptversammlung_2024.pdf

A consistent schema creates order:

20211210_Einladung_JHV_2022.pdf
20221209_Einladung_JHV_2023.pdf
20231208_Einladung_JHV_2024.pdf

Designing a consistent filing system is not difficult. Still, such initiatives often fail. Even the best system has limited value if few people follow it.

For solo professionals, consistent naming is easier to implement. In small teams, it can work well. In larger companies, there are often too many contributors involved. Human factors such as convenience, impatience, or individual preferences are hard to eliminate and often prevent consistent execution.

Conclusion

Implementing a well designed file naming system is more than a matter of personal organization. It is an operational decision that improves access to digital content, supports information sharing, and increases productivity, if everyone follows it. This cannot be taken for granted. The best practices described here only have value if contributors can be guided to apply them consistently.

This makes two priorities essential:

New employees should be sensitized to the topic from the start and receive sufficient onboarding.
A foundational training should be considered that covers not only file names, but professional file management as a whole, including Digital Asset Management.

File naming reaches its full potential only when combined with:

Meaningful folder structures
Optimized metadata