What is the AHS file format?
An .ahs file is an Adobe Photoshop Halftone Screens preset - a small binary settings file that stores halftone screen parameters for use in commercial print production. It is created and loaded through Adobe Photoshop.
Halftone screening converts a continuous-tone image into a dot pattern for printing on press. Each color channel - Cyan, Magenta, Yellow, and Black in CMYK, or a single Gray channel - is assigned three parameters:
- Frequency - screen ruling in lines per inch (lpi) or lines per centimeter
- Angle - screen angle in degrees (-180 to +180)
- Dot shape - Round, Diamond, Cross, Line, Square, or Custom
These per-channel settings are exactly what an .ahs file stores. The file opens with the four-byte signature 8BHS (0x38 0x42 0x48 0x53), following Adobe's 8B-prefix convention used across Photoshop preset types such as .atn action files and .abr brush presets. Data is encoded in big-endian binary; files are typically under 1 KB.
In Photoshop, halftone screen settings are accessed via Image > Mode > Bitmap > Use: Halftone Screen, where a Save button exports the current configuration as .ahs. They are also reachable through File > Print > Output > Screens. Outside dedicated prepress and print production workflows - offset lithography, screen printing - most Photoshop users never encounter this format.
Security & safety
RISK: LOWBinary preset file; contains only numeric print parameters; no executable code; no security risk.
Format details
in a nutshellPrograms that open AHS files
Windows1 app
Adobe Photoshop
Paid (creative cloud subscription) Image > Mode > Bitmap > Use: Halftone Screen > Load... to apply; or File > Print > Output > Screens > Load. To save new AHS: use Save... in the same dialog. 
macOS1 app
Adobe Photoshop
Paid (creative cloud subscription) Image > Mode > Bitmap > Use: Halftone Screen > Load... to apply AHS settings. Technical details
deep spec| Encoding | Binary |
| Byte order | Big-endian (Adobe Photoshop preset format convention) |
| Magic bytes | 8BHS (0x38 0x42 0x48 0x53) at offset 0 - Adobe 8B-prefix preset family |
| Typical file size | Under 1 KB |
| Parameters stored | Per-channel halftone screen frequency (lpi), angle (degrees), and dot shape |
| Supported dot shapes | Round, Diamond, Cross, Line, Square, Custom |
| Frequency range | 1-999.999 lines per inch (lpi) or lines per centimeter |
| Angle range | -180 to +180 degrees per channel |
| Color modes | Grayscale (single channel) or CMYK (four channels: C, M, Y, K) |
| Access in Photoshop | Image > Mode > Bitmap > Halftone Screen (Save/Load), or File > Print > Output > Screens |
| Use context | Prepress and commercial print production (offset lithography, screen printing) |
| Associated OS | Windows and macOS (wherever Adobe Photoshop runs) |
| Released | early 1990s (Adobe Photoshop; exact version undocumented; present in PS 4+ era) |
AHS conversions
Community Q&A
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