JEDMICS. Joint Engineering Data Management Information and Control System.
A plain-English reference for the U.S. Department of Defense's engineering-drawing repository system, its current program status, and the .C4 file format it produced.
What JEDMICS is, in plain English
JEDMICS is a repository for unclassified U.S. Department of Defense engineering and technical data. The official program site describes its purpose directly:
“JEDMICS is a repository that stores unclassified engineering and related technical data. JEDMICS supports multiple disciplines that include material management, maintenance repair and depot level overhaul, engineering, acquisition, and sustainment efforts.” jedmics.net
Historically, JEDMICS has been the primary way federal contractors and DoD personnel exchanged engineering drawings with the services. Drawings were stored as .C4 files, a compact black-and-white raster format using the same CCITT Group 4 compression as fax machines, and distributed via service-specific portals and solicitations.
Starting in 2025, two of the largest service users began transitioning to newer systems. Many historical .C4 files remain in circulation, which is why a standalone viewer is still useful.
The .C4 file format
A .C4 file is a single-page or multi-page black-and-white raster image, compressed with ITU-T T.6, better known as CCITT Group 4 facsimile compression. It was designed for line-art engineering drawings, where the image is mostly white paper with sharp black linework, tables, and annotations.
The format is efficient for that specific case (a 34×44-inch scanned drawing typically fits in 200 to 600 KB), but opening it requires software that understands the JEDMICS-specific wrapper around the raw CCITT G4 data. Most general-purpose image viewers cannot open .C4 directly.
The official JEDMICS C4 Image Specifications document is hosted on jedmics.net's public specs page. It was last revised on 15 April 2002 and remains the authoritative definition.
Frequently asked
Is this an official DoD site?
No. This is an independent informational reference operated by Secureframe. It is not affiliated with the DoD, the Navy, or the JEDMICS program. The official JEDMICS program pages are at jedmics.net.
Can I access JEDMICS through this site?
No. This site does not provide access to JEDMICS accounts, drawings, or other DoD systems. Registered JEDMICS users should refer to jedmics.net or to their service's current successor system (AvPLM for NAVAIR, A-TEAM for the Air Force).
I still have .C4 files from old DIBBS solicitations. How do I open them?
Use c4file.com. It's a free browser-based viewer and converter. The file stays on your device, and you can export to PDF, TIFF, PNG, or JPEG.
What happened to NAVAIR JEDMICS?
Per jedmics.net, NAVAIR users lost access to JEDMICS on 2 September 2025. Naval Air technical data is now exclusively viewed and managed through AvPLM, the new Naval Air program of record. See the AvPLM Customer Portal, linked from jedmics.net, for current information.
What happened to Air Force JEDMICS?
Per jedmics.net, the Department of the Air Force JEDMICS has been replaced by A-TEAM, the All-purpose Tool for Engineering, Analytics, and Management.
Why does the C4 format's spec still say April 2002?
The JEDMICS C4 Image Specifications document on jedmics.net is dated 15 April 2002 and has not been updated since. The format itself is stable. It wraps CCITT Group 4 data, which is a long-standing ITU-T standard, so updates haven't been needed.