Git Push Error: HTTP 400 RPC Failed - Solutions

Problem Statement

When attempting to push code to a GitHub repository (especially private repositories), you might encounter this error:

RPC failed; HTTP 400 curl 22 The requested URL returned error: 400
send-pack: unexpected disconnect while reading sideband packet

This error indicates a failure during the Git push operation that prevents your files from appearing in the repository. It commonly occurs when:

• Pushing large commits or binary files
• Using outdated Git clients
• Encountering GitHub connection limitations
• Having underlying authentication issues

The error arises because Git's default HTTP buffer size cannot handle large data transfers, causing the server to terminate the connection prematurely.

Recommended Solutions

1. Increase Git HTTP Buffer Size

The most effective solution adjusts Git's network buffer to handle larger payloads:

Global Configuration (Recommended)

git config --global http.postBuffer 524288000  # 500 MB

Repository-Specific Configuration

git config http.postBuffer 157286400  # 150 MB

Why this works: Git's default buffer (~1 MB) can't handle large commits. Increasing it prevents timeouts during data transfer.

2. Update Git to the Latest Version

Outdated Git versions often cause compatibility issues:

::: code-group-item macOS (Homebrew)

bash

brew update && brew upgrade git

::: ::: code-group-item Windows Download latest installer from git-scm.com ::: ::: code-group-item Linux (Debian/Ubuntu)

bash

sudo apt update && sudo apt install git --upgrade

:::

PATH Conflicts

Verify your active Git version with git --version. If multiple installations exist, ensure your PATH points to the updated version.

3. Optimize Large Commit Management

Reduce push payload size using these strategies:

Push smaller batches

git push origin master --max-count=50  # Push last 50 commits

Enable thin pushes (reduces network data):

git push --thin origin master

Use Git LFS for large files
Install Git LFS then track large files:

git lfs install
git lfs track "*.psd" "*.zip"
git add .gitattributes

4. Verify GitHub Authentication

Renew access tokens if expired:

1. Visit GitHub Tokens Settings
2. Generate a new classic token with repo scope
3. Update your Git credentials:

git config --global credential.helper store
git fetch  # Will prompt for new credentials

5. Repository Maintenance

Clean up unnecessary files with garbage collection:

git gc --auto
git repack -a -d --depth=250 --window=250

Solution Comparison

Approach	When to Use	Limitations
Increase http.postBuffer	Large binary files/assets	Not effective for extremely large repos
Git/Client Update	Older Git installations (versions < 2.30)	Requires environment changes
Smaller Batches/LFS	Repositories exceeding 1GB	Requires commit restructuring
Authentication Refresh	Token-related connection issues	Doesn't resolve push size issues

Preferred Workflow

1. Start with buffer size increase
2. Update Git client
3. Implement LFS for binary assets
4. Push in smaller batches as last resort

Additional Considerations

• GitHub file limit: Files >100MB require Git LFS
• Network stability: VPN/proxy connections may interrupt pushes
• Repository size: Repositories >5GB may require archiving old assets

If these solutions fail, contact GitHub Support with your repository details and error logs.

Important

Avoid repeatedly attempting pushes without making changes - this won't resolve the underlying issue and may trigger abuse detection.