Why Github Don't Allow Files over 100 MB? And How to Use Git LFS?

[DalipM]

Discussion Type

Question

Discussion Content

I am currently working on a dental clinic project, where we are making a system to manage patient's data and X-ray files. While pushing the X-ray files, I encountered an error stating: You can't upload a file above 100 MB. My file is of 115MB and of .dcm file type. I went online and found out that I need to use Git LFS. Honestly, I have never used the Git LFS before. Can somebody please Guide me about Git LFS? Thank you in advance.

[Laibah-Shahid]

Hey! 👋

You're on the right track. Git does have a 100MB file size limit, and that's exactly where Git LFS (Large File Storage) comes in. It’s designed to help manage large files, such as .dcm, .psd, and videos, without bloating your main Git repository.

Here’s a quick step-by-step to get started with Git LFS:

1. Install Git LFS (only once per machine):
   git lfs install

2. Track your .dcm files:
   git lfs track "*.dcm"

3. Make sure the .gitattributes file is committed (Git LFS creates it automatically):
   git add .gitattributes

4. Then just add and push your file like usual:
   git add your-xray-file.dcm
   git commit -m "Added X-ray file"
   git push origin main

⚠️ If you're using GitHub, make sure Git LFS is enabled on your repo (and keep an eye on GitHub’s LFS storage limits; free accounts get a default quota).

[mecodeatlas]

Thanks for posting in the GitHub Community, @DalipM!

We're happy you're here. You are more likely to get a useful response if you are posting your question in the applicable category, the Discussions category is solely related to conversations around the GitHub product Discussions. This question should be in the Programming Help category. I've gone ahead and moved it for you. Good luck!

[IT22194930]

Hi @DalipM! Great question.

❓ Why Does GitHub Block Files Over 100MB?

GitHub limits file uploads to 100 MB for performance and efficiency reasons:

• Large files bloat the Git history and slow down cloning.
• Repositories are meant for source code, not binary assets like large media or data files.

To handle large files like .dcm (DICOM X-ray images), GitHub recommends using Git LFS (Large File Storage).

---

🧰 What is Git LFS?

Git LFS replaces large files in your repository with lightweight pointers, while the actual files are stored outside GitHub's standard Git system — but still versioned and linked.

---

🚀 How to Use Git LFS (Step-by-Step)

1. Install Git LFS

   Download and install it from:
   👉 https://git-lfs.github.com/

   Or use a package manager:

   # macOS
   brew install git-lfs
   
   # Ubuntu
   sudo apt install git-lfs
   
   # Windows
   choco install git-lfs
   

2. Initialize Git LFS in your repo

   git lfs install
   

3. Track your large file type (e.g., .dcm)

   git lfs track "*.dcm"
   
   This creates a .gitattributes file. Make sure to commit it:
   ```bash
   git add .gitattributes
   

4. Add and commit your large files

   git add path/to/your/large-file.dcm
   git commit -m "Add X-ray file using Git LFS"
   

5. Push your changes

   git push origin main
   

⚠️ Notes

Git LFS has a free quota of 1 GB storage + 1 GB bandwidth per month.

[V1vek-kushwaha]

GitHub imposes a hard limit of 100 MB per file for several reasons

1. Performance & Storage Optimization
   Git is designed for source code, which is usually text-based and small in size. Pushing large binary files:

Bloats the repository
Slows down cloning and fetching
Increases storage costs

2. Versioning Overhead
   Every change to a large file creates a new version. Without compression or delta handling (which Git doesn’t do well for binaries), this quickly makes the repo unmanageable.

-------------How to Use Git LFS (Step-by-Step)---------
Step 1
git lfs install

Step 2
git lfs track "*.dcm"

Step 3
git add .gitattributes
git add path/to/your-xray-file.dcm
git commit -m "Add X-ray file using Git LFS"

Step 4
git push origin main

note-GitHub provides 1 GB of LFS storage and 1 GB/month of bandwidth for free.

[houkyz]

Discussion Type

Question

Discussion Content

I am currently working on a dental clinic project, where we are making a system to manage patient's data and X-ray files. While pushing the X-ray files, I encountered an error stating: You can't upload a file above 100 MB. My file is of 115MB and of .dcm file type. I went online and found out that I need to use Git LFS. Honestly, I have never used the Git LFS before. Can somebody please Guide me about Git LFS? Thank you in advance.

!!!