A free converter for JEDMICS .C4 engineering drawings. Files process in your browser. Nothing is sent to our servers. Made for federal contractors and DoD personnel who need to open C4 drawings without handing them to a third party.
A .C4 file is a raster image used by JEDMICS, the DoD's Joint Engineering Data Management Information and Control System. It stores engineering drawings compressed with CCITT Group 4 (ITU-T T.6). That's the same format used by black-and-white fax machines.
If you have one, it came from one of these systems:
.C4 technical attachments.What “runs in your browser” means, if you are not a software engineer:
On your first visit, your browser downloads the tool. It's a small program compiled to WebAssembly, about 1 MB. After that download, the tool lives on your device.
When you drop a .C4 file in, your own laptop, phone, or tablet does the decoding and re-encoding. The file stays in your device's memory. Nothing goes back to us or to anyone else. Once the page is loaded, conversion itself does not touch the network.
This is different from most “online converters,” which send your file to a stranger's server, process it there, and send you back the result. For engineering drawings that may be sensitive or proprietary, that kind of upload is a risk. C4File.com removes it at the architectural level: there is no server to upload to.
Read the full security page for the verification walkthrough →
Contractors often receive batches of .C4 attachments. Sometimes dozens per solicitation. C4File.com handles batches directly:
.C4 files onto the converter, or use the file picker with Shift-click to multi-select.converted.zip download contains the set.Because conversion runs on your hardware, the practical batch size depends on your device's memory. No cloud quota. A modern laptop can easily handle 100-200 typical drawings.
Yes. Unlimited conversions, no signup, no watermarks, no feature gates.
No. Every conversion runs on your device. Open your browser's Developer Tools, go to the Network tab, drop a .C4 file: no requests go out with your file data.
No hard cap from us, because there is no server. Your device does the work, so the real limit is the memory your browser has available. In practice: a modern laptop can easily handle 100-200 typical drawings. The converter processes batches in a queue and stops with a clear error if the browser reports low memory.
Yes. After your first online visit, your browser caches the converter, viewer, WebAssembly decoder, and core assets. You can reopen C4File.com on the same device and convert or view C4 files without a network connection.
No install is required. The viewer runs in your browser on Windows, Mac, Linux, Chromebook, iPad, iPhone, and Android. Open the C4 viewer, choose a .C4 file, inspect it, then download PDF, TIFF, PNG, or JPEG.
Yes. PDF is the default output because it is easiest for review packets, printing, email, and sharing with people who do not have a C4 or JEDMICS viewer.
Use PDF for sharing and printing, TIFF for archival or imaging workflows, PNG for lossless embedding in documents and web pages, and JPEG only when a smaller preview is more important than exact line fidelity.
Yes. The converter runs on iPad, iPhone, Android, Chromebook, and any other device with a recent browser. Single-file conversion works everywhere. Large batches are easier on a laptop because of memory headroom.
PDF, TIFF, PNG, and JPEG. If you need another format for your workflow, email [email protected] and tell us what and why.
C4File.com is built and run by Secureframe, a US cybersecurity company. Secureframe helps companies achieve CMMC, FedRAMP, SOC 2, ISO 27001, and more.