# How to send CAD and BIM files without breaking references

Source: https://help.strongfolder.com/en/guides/send-cad-files/
Updated: 2026-11-05

> To send CAD files without broken references, package the project with eTransmit or Pack and Go into a folder that uses relative paths, then send that folder as a folder. StrongFolder streams it straight to the recipient's browser — subfolders kept, no ZIP, no upload, no size limit set by the service. For ongoing collaboration, use a common data environment.

1. **Set relative paths** — Make sure xrefs and linked models use relative paths and sit inside the project folder (not on another drive).
2. **Package the project to a folder** — Run eTransmit (AutoCAD, Revit) or Pack and Go (SolidWorks) and choose a folder as the output, so every dependent file is collected.
3. **Choose the folder in StrongFolder** — Open [strongfolder.com](https://strongfolder.com) or the Chrome extension, click **Upload Folder** and pick the packaged folder. Nothing is uploaded.
4. **Send the link** — Send the link by e-mail or chat to the consultant, contractor or client.
5. **Keep the tab open** — The recipient saves the same folder tree and opens the host file. Keep your tab open until they finish.

When you send CAD files, you are rarely sending one file. A drawing references xrefs, images
and fonts; a Revit model links other models and CAD files; a SolidWorks assembly is a tree of
parts. Each of those links is a **file path**. Change the folder layout on the way, and the
recipient opens a drawing full of missing references. This guide shows how to package a
project so the paths survive, and how to send CAD and BIM files as one intact folder.

**Key facts**

- CAD and BIM files point to each other by **path** — the folder structure is part of the data.
- Use **relative paths** and keep every reference **inside the project folder**.
- Package with **eTransmit** (AutoCAD, Revit) or **Pack and Go** (SolidWorks), output to a **folder**.
- **Direct P2P transfer** (StrongFolder) sends that folder as is: no ZIP, no upload. No size limit set by StrongFolder. The practical limits are free disk space on the recipient's device, connection speed, and how long both devices stay online.
- The trade-off: **your tab must stay open** until the recipient finishes.

## Why does folder structure matter for CAD files?

Every major CAD and BIM tool stores references as paths:

| Software | What is referenced | How the path is stored | Packaging tool |
|---|---|---|---|
| AutoCAD | Xrefs, images, PDF/DWF underlays, fonts, plot styles | Full (absolute), relative or no path, per reference | eTransmit |
| Revit | Linked Revit models, CAD links, images | Relative or absolute ("Path Type" in Manage Links) | eTransmit for Revit |
| SolidWorks | Parts in an assembly, drawings of parts and assemblies | Path to each referenced document | Pack and Go |

**Absolute paths** (`P:\Projects\2026\Tower\xref\grid.dwg`) break as soon as the recipient's
drives are named differently. **Relative paths** (`..\xref\grid.dwg`) keep working wherever
the project folder lands — *as long as the subfolders arrive exactly as you sent them*.

That second condition is where many transfer methods fail. Email can't carry folders.
Cloud drives keep the tree online but usually zip it on download, so the recipient must
extract it to the right place. Some tools flatten folders into a list of files, which breaks
relative paths outright.

## How do I prepare a CAD project for sending?

### AutoCAD: relative xrefs and eTransmit

1. In the **External References** palette, check that each xref uses a **relative** path.
   An xref on a different drive from the host drawing can't be stored as relative — move it
   into the project folder first.
2. Run **eTransmit** and choose a **folder** as the transmittal type, so the package is a
   plain folder rather than an archive.
3. Read the transmittal report for missing files before you send anything.

### Revit: links and eTransmit for Revit

1. Open **Manage Links** and look at the **Path Type** column: links should be relative.
2. Close the models and run **eTransmit for Revit**. It copies the host model and its
   dependent files and converts absolute paths into relative paths or no path, so the
   dependent files can be found in the package.
3. For a workshared model, send a **detached** copy — the recipient should not work on a
   copy of your central model.

### SolidWorks: Pack and Go

**Pack and Go** gathers the related files of a design — parts, assemblies, drawings and other
references — and copies them into a folder or a ZIP file. Choose the folder option, and
include drawings if the recipient needs them.

## How do I send the CAD project folder?

Once the project is packaged as a folder, send it as a folder:

1. Open StrongFolder and click **Upload Folder**.
2. Pick the packaged project folder. Nothing is uploaded; the browser only reads the tree.
3. Send the link to the consultant, contractor or client.
4. They choose where to save it and get the same folder tree, then open the host file —
   relative references resolve on the first try.

Folders are sent as folders: subfolders and file names are kept, nothing is zipped. Saving a whole folder with its structure uses the File System Access API: Chrome, Edge, Opera and other Chromium browsers on a computer. Other browsers can download the files one by one or as a ZIP.

[Send files now](https://strongfolder.com)
## Which method should I use to send large CAD files?

| Method | Folder structure | Free size limit | Upload first? | Sender online? | Best for |
|---|---|---|---|---|---|
| Email | No | ~20–25 MB | Yes | No | One small DWG or PDF |
| Cloud drive (Google Drive, OneDrive, Dropbox) | Kept online, usually zipped on download | Your storage quota | Yes | No | Files that must stay available |
| CDE (Autodesk Docs, other project platforms) | Yes, managed | Plan-based | Yes | No | Ongoing multi-party collaboration |
| Transfer service (WeTransfer-type) | Usually zipped | Check the vendor's current plan | Yes | No | Occasional one-off sends |
| **StrongFolder (P2P)** | **Kept, no ZIP** | **None set by the service** | **No** | **Yes** | Fast handoff of a packaged project |

Big projects add up quickly: a federated BIM model with links and a laser-scan point cloud
can reach tens or hundreds of gigabytes. Any internet transfer is limited by the sender's
upload speed — 50 GB at 100 Mbit/s takes at least about 67 minutes (400 gigabits ÷ 100
Mbit/s), at 50 Mbit/s about 2.2 hours. A direct transfer avoids doing that wait twice
(upload, then download).

## When should I not use StrongFolder for CAD files?

- **The team works on the same models every day.** Use a common data environment or PDM/vault
  system with version control, permissions and an audit trail.
- **A contract requires a formal transmittal record** in a specific platform. Follow it.
- **You can't keep your computer on** until the recipient finishes. The sender's browser tab must stay open and online until the recipient finishes downloading — files come from the sender's device, not from a server.
- **The recipient will open the link on a phone or tablet** and needs the folder structure.
  Saving a whole folder needs a Chromium browser on a computer.

## Is it secure enough for project files?

WebRTC encrypts every data channel with DTLS, so the file stream is encrypted in transit on every connection. Files are never uploaded to or stored on a StrongFolder server. To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files. If a direct connection is impossible (strict corporate firewall, some mobile networks), the encrypted stream passes through a StrongFolder relay (TURN) server. The relay forwards the data and does not store it. Anyone with
the link can download while you share, so send it directly to the intended recipient and
click **Stop Sharing** when they confirm receipt. See [Security & privacy](https://help.strongfolder.com/en/security/) and
[secure file sharing](https://help.strongfolder.com/en/guides/secure-file-sharing/).

## Summary

To send CAD files without broken references, make paths relative, keep every reference in
the project folder, package with eTransmit or Pack and Go into a folder, and send that folder
as a folder. A direct peer-to-peer transfer does the last step without a ZIP or an upload;
a common data environment remains the right home for day-to-day collaboration. For drawings
and PDFs, see [How to send large documents](https://help.strongfolder.com/en/guides/send-large-documents/); for folders in
general, [How to send a folder without zipping it](https://help.strongfolder.com/en/guides/send-folder-without-zipping/).

## FAQ

### Why do xrefs break when I send a drawing?

The host drawing stores the path to each xref. If the path is absolute (for example a drive letter on your network) or the files arrive in a different folder layout, AutoCAD can't find them. Use relative paths, keep xrefs inside the project folder, and send the folder with its structure.

### Should I zip CAD files before sending?

Only if the channel can't carry folders. A ZIP keeps relative paths, but the recipient must extract it to the right place, and very large archives take time and disk space twice. Sending the packaged folder as a folder avoids that.

### How do I send a Revit model with its links?

Close the models and use eTransmit for Revit, which copies the host model and its linked files and rewrites absolute paths as relative or no path. For a workshared model, send a detached copy rather than the central file.

### How do I send a SolidWorks assembly?

Use Pack and Go. It gathers the assembly, its parts, drawings and other references into a folder or a ZIP. Choose a folder, then send that folder.

### Is there a size limit for CAD or point-cloud files?

No size limit set by StrongFolder. The practical limits are free disk space on the recipient's device, connection speed, and how long both devices stay online.

### Is it secure enough for confidential drawings?

WebRTC encrypts every data channel with DTLS, so the file stream is encrypted in transit on every connection. Files are never uploaded to or stored on a StrongFolder server. Anyone who has the link can download while you share, so send it only to the intended recipient and click Stop Sharing afterwards.