# GitHub520: Fix Slow GitHub Access by Updating Your Hosts File

> GitHub520 is a Python-backed service that publishes an optimized hosts file mapping GitHub domains to their best-performing IP addresses, improving page load speed and restoring missing images for users who experience degraded GitHub access. No software needs to be installed on the client machine.

**521xueweihan/GitHub520** — :kissing_heart: 让你“爱”上 GitHub，解决访问时图裂、加载慢的问题。（无需安装）

- Repository: https://github.com/521xueweihan/GitHub520
- Stars: 29,893 · Forks: 2,762
- Language: Python
- License: not declared
- Published: 2026-09-21 · Updated: 2026-09-21 · Language: en
- Canonical page: https://hysenlabs.com/projects/521xueweihan-github520

## The Problem GitHub520 Addresses

GitHub serves its assets, including project images and avatars, from content delivery network hostnames that can resolve to slow or unreachable IP addresses depending on the local DNS resolver. The symptom is a GitHub page that loads slowly or displays broken image placeholders where project screenshots and diagrams should appear.

GitHub520 addresses this by maintaining a hosts file that maps GitHub-related hostnames to IP addresses measured to perform best from a given vantage point. By adding those entries to the system hosts file, DNS lookups for those hostnames bypass the resolver and use the pre-measured IPs directly.

The README positions this as a five-minute, no-install fix. Nothing is installed on the machine; the only change is a block of text added to the system hosts file. This also means the improvement is limited to the domains in the hosts file: GitHub domains not covered by the list will still resolve through the standard DNS path.

## How the Hosts Data Is Generated

The repository contains Python scripts that automate IP measurement. The files fetch_ips.py and update_ips.py run periodically to test IPs for each GitHub hostname and update the hosts file when a better-performing IP is found. The README notes that the hosts content updates automatically and that content is not re-published if the IPs have not changed.

The requirements.txt lists the measurement dependencies: requests-html, pythonping, retry, aiodns, and lxml_html_clean. The pythonping library provides ICMP ping from Python, suggesting the IP selection is at least partly based on ping latency rather than purely HTTP throughput.

The generated hosts data is published at two endpoints that clients can fetch directly without visiting GitHub:
- File format: https://raw.hellogithub.com/hosts
- JSON format: https://raw.hellogithub.com/hosts.json

The README shows a sample of the hosts block. The format starts with a comment marker:

```bash
# GitHub520 Host Start
140.82.112.25                 alive.github.com
20.205.243.168                api.github.com
185.199.110.133               avatars.githubusercontent.com
```

The block is bookended by # GitHub520 Host Start and # Github520 Host End markers, which the one-line update scripts use to identify and replace the block.

## Applying the Hosts File: Manual, Automatic, and One-Line Methods

The manual method copies the hosts block from the README or from https://raw.hellogithub.com/hosts and appends it to the system hosts file. The file location varies by OS:
- Windows: C:\Windows\System32\drivers\etc\hosts
- Linux and macOS: /etc/hosts
- Android: /system/etc/hosts (requires root)
- iPhone and iPad: /etc/hosts (requires jailbreak)

After editing, DNS must be flushed. On Windows:

```bash
ipconfig /flushdns
```

On macOS:

```bash
sudo killall -HUP mDNSResponder
```

The SwitchHosts tool (a third-party hosts manager referenced in the README) automates this by polling https://raw.hellogithub.com/hosts on a one-hour interval and applying changes without manual steps. Configure it by setting the hosts type to Remote, the URL to https://raw.hellogithub.com/hosts, and the auto-refresh to 1 hour.

For users who prefer a single command on Linux or macOS, the README provides shell one-liners. The macOS version:

```bash
sudo sed -i "" "/# GitHub520 Host Start/,/# Github520 Host End/d" /etc/hosts && curl https://raw.hellogithub.com/hosts | sudo tee -a /etc/hosts
```

This removes any existing GitHub520 block and appends the latest one. The README includes a variant for Docker containers that avoids the Device or resource busy error by copying the hosts file to a temp location first.

AdGuard users (desktop or mobile) can subscribe to the hosts file as a DNS blocklist filter at the same URL, with a one-hour refresh interval set in AdGuard's general settings.

## Limitations: Mobile Devices and Service Dependency

On Android, modifying /system/etc/hosts requires root access. On iPhone and iPad, it requires a jailbreak. The README does not provide a workaround for non-rooted mobile devices beyond the AdGuard option, which is available for iOS and Android in their respective AdGuard apps.

The more significant limitation is the dependency on raw.hellogithub.com. All automated refresh methods fetch data from that server. The README contains a note that the server will expire on 2026-12-31 and that renewal requires 831 yuan per year. If the server goes offline, clients configured for automatic refresh will stop receiving updates and the stale IPs in the local hosts file may become inaccurate over time. Teams integrating this into an automated setup should monitor for that service disruption.

The hosts approach also has a structural limit: it only corrects domains that are in the generated list. GitHub domains added later will not benefit until the list is updated.

## GitHub520 vs a Proxy Approach

Ghproxy is an alternative approach that operates as a reverse proxy for GitHub file downloads rather than a DNS-level redirect. The practical difference is scope: a proxy like Ghproxy accelerates file downloads from GitHub repositories by caching or routing through a faster path, but it does not fix GitHub's web interface or image rendering. GitHub520 addresses the web interface and assets directly through the hosts file but has no effect on download speeds for archive files or large binary assets.

The two tools target different symptoms of the same underlying connectivity issue. A developer who primarily experiences slow git clone operations would not benefit from GitHub520 alone, while one who mainly sees broken images and slow page rendering gets no help from a download proxy.

The licence for GitHub520 is CC BY-NC-ND 4.0, which prohibits commercial use and derivative works. Ghproxy and similar proxy tools carry their own licences and terms.

## Maintenance Status and Licence

The last push to the repository was on 2026-09-28, with automated updates to the hosts data running continuously. The repository has no GitHub releases; the hosts content itself is the deliverable, updated in-place rather than versioned.

The licence is CC BY-NC-ND 4.0 (Attribution-NonCommercial-NoDerivatives). This is not an open-source licence by the OSI definition: it prohibits commercial use and does not permit derivative works. The tools and scripts in the repository are covered by this licence, not by an OSI-approved licence like MIT or Apache-2.0. Teams integrating the scripts rather than just consuming the hosted data need to verify that this licence is compatible with their use.

## Conclusion

GitHub520 is a practical tool for developers who experience consistently slow GitHub page loads or broken image rendering and cannot use a VPN or proxy. It is not a substitute for a proxy in environments where the root cause is deep packet filtering rather than DNS-level misdirection, and it will not help on Android or iOS devices without root or jailbreak. The service depends on a server at raw.hellogithub.com whose funding renewal is documented in the README as due on 2026-12-31; anyone relying on the auto-refresh URL should confirm the server remains operational before that date.

## FAQ

### How do I use GitHub520 on macOS?

Run the one-line command: sudo sed -i "" "/# GitHub520 Host Start/,/# Github520 Host End/d" /etc/hosts && curl https://raw.hellogithub.com/hosts | sudo tee -a /etc/hosts. Then flush DNS with sudo killall -HUP mDNSResponder. For automatic updates, configure SwitchHosts with the URL https://raw.hellogithub.com/hosts on a one-hour refresh.

### Does GitHub520 work on Android?

Modifying the hosts file on Android requires root access. The README notes that /system/etc/hosts on Android must be modified with root, so the tool does not work on unrooted devices. AdGuard for Android can subscribe to the hosts URL as a DNS filter without root.

### What domains does GitHub520 cover?

The hosts file covers GitHub-related domains including alive.github.com, api.github.com, and avatars.githubusercontent.com, among others. The README shows a partial sample; the full list is published at https://raw.hellogithub.com/hosts and is updated automatically when better IPs are found.

## Sources

- [521xueweihan/GitHub520 on GitHub](https://github.com/521xueweihan/GitHub520)
- [Issues](https://github.com/521xueweihan/GitHub520/issues)
- [README](https://github.com/521xueweihan/GitHub520/blob/main/README.md)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/521xueweihan-github520