atm

.atmATM File

Microsoft · 1992

Developer
Microsoft
Category
Images
MIME Type
image/x-windows-bmp
First Released
1992
Open Format
Yes
File Signature
No widely recognized standard magic bytes; often identified by context or application-specific headers.
At a Glance
.atm
ATM File

An ATM file is a raster image format, primarily used for icons and simple graphics in older Windows applications.

Reviewed on July 13, 2026
Compression
Uncompressed
Transparency
No
Editability
High
Best for
Icons and cursors

Key Features

  • Raster image format based on pixels.
  • Uncompressed, leading to direct pixel data.
  • Simple structure, easy to parse.
  • Primarily used for UI elements like icons and cursors.

Best For

  • Simple, small icons with limited color palettes.
  • Situations requiring direct pixel access.
  • Compatibility with very old Windows software.
  • Creating basic UI elements where file size is not a major concern.

Less Ideal For

  • Photographic images due to lack of compression.
  • Web use where file size is critical.
  • Images requiring transparency (unless specific variations exist).
  • Complex graphics with many colors and gradients.

Common Use Cases

  • Storing icons for Windows applications.
  • Displaying cursors and other small graphical elements.
  • Used in legacy software for graphical assets.
  • Basic image manipulation in older development environments.

How to Open It

  1. Open in image editing software like GIMP or Paint.NET.
  2. Use dedicated icon editing tools if available.
  3. Convert the file to a more common format like PNG or BMP first.
  4. Many file archivers might also be able to extract them if embedded.

What is a .atm file?

An ATM file is essentially a bitmap image format, often associated with older Windows applications and graphical user interfaces. It's a raster image format, meaning it stores images as a grid of pixels. While not as common today as formats like JPG or PNG, it served a purpose in early computing environments for displaying icons, cursors, and simple graphics. These files can sometimes be encountered when working with legacy software or specific development tools that still utilize this format for their assets. Understanding its nature as a bitmap is key to working with it effectively.

Programs That Open .atm Files

PlatformProgram
WindowsMicrosoft PaintFreeOfficial
GIMPFree
Paint.NETFree
macOSGIMPFree
PreviewFreeOfficial
LinuxGIMPFree
KolourpaintFree

How to Convert .atm Files

FormatMethod
.PNGImage editing software (GIMP, Photoshop), Online converters
.BMPImage editing software, File conversion utilities

Common Problems with .atm Files

⚠️ Cannot open ATM file directly in modern software.
Convert the file to a more common format like PNG or BMP using image editing software or online tools.
⚠️ File size is unexpectedly large for a simple image.
This is typical as ATM is often an uncompressed format; consider converting to a compressed format like PNG for better efficiency.

Frequently Asked Questions

Is ATM a common image format today?

No, ATM is an older format primarily used for specific purposes in legacy Windows applications and is not widely supported or used for general image storage today.

Can ATM files support transparency?

Typically, standard ATM files do not support transparency, similar to basic BMP files. Specialized variations might exist, but it's not a common feature.

What's the difference between ATM and BMP?

ATM files are very similar to BMP files, often being an uncompressed bitmap format. The distinction can be subtle and sometimes depends on the specific application that generated the ATM file; they are often interchangeable or variations of the same underlying technology.

Technical Details

ATM files are typically uncompressed bitmaps, similar to BMP files, and are stored as raw pixel data. They lack sophisticated compression techniques, leading to larger file sizes compared to modern image formats. The structure often includes a header describing the image dimensions and color depth, followed by the pixel data itself. Due to their uncompressed nature, they offer straightforward pixel manipulation but are not ideal for photographic images.

Did You Know?

The .atm extension might stand for 'Actual Transfer Machine' in some contexts, but in image files, it's generally associated with bitmap data.
ATM files are pixel-based, meaning they are composed of a grid of colored dots, rather than vector-based images which use mathematical equations.

Security Information

ATM files, like other image formats, generally pose a low security risk. However, as with any file from an untrusted source, it's advisable to open them in sandboxed applications or conversion tools to prevent potential vulnerabilities if the file were maliciously crafted.

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