GitHub Bus Factor Checker
Paste any public GitHub repo and get its bus factor: how few people wrote half the commits. A real, live read on how concentrated a codebase's knowledge is.
Paste any public GitHub repository and this tool reads back its bus factor: the smallest number of people who, between them, wrote half of all the commits. It is a fast, real read on how concentrated a codebase’s knowledge is, pulled live from data GitHub already makes public.
A low bus factor is not a person’s fault. It is a structural risk: if one or two people account for most of the history, the team is one resignation or one long holiday away from a codebase nobody fully understands. This tool measures the exposure, not the individuals.
Everything runs in your browser against the public GitHub API. No login, no token, no private access, and nothing about the repo is sent to CodePulse.
Enter a public repository to see how concentrated its knowledge is.
How it’s calculated
The tool runs a short sequence of calls against the public GitHub REST API. No token is sent, so it shares the unauthenticated budget of 60 requests per hour per IP. Every response updates the rate-limit counter shown under the search box.
What it fetches
- Repository metadata from /repos/{owner}/{repo}: description, stars, primary language.
- The contributor list from /repos/{owner}/{repo}/contributors, up to 300 people, with each person’s commit count to the default branch.
How the bus factor is calculated
- Bots (logins containing "[bot]") are excluded.
- Contributors are sorted by commit count, highest first.
- The bus factor is the smallest number of top contributors whose commits add up to at least 50% of the total. This is the widely used "half the knowledge" heuristic.
- Knowledge concentration is the share of all commits held by the single largest contributor, and by the top three combined.
This is a commit-based proxy, not a per-file ownership analysis. It counts commits to the default branch only, and GitHub’s contributor counts are approximate for very large repositories. Treat the number as a strong signal, not an exact score.
Worked example
Say a repo has 40 contributors but the top two account for 30% and 22% of commits. Cumulatively that is 52%, which crosses the halfway line, so the bus factor is 2.
A bus factor of 2 on a 40-person project is a real flag: despite the crowd, the knowledge sits with two people. The read is not "those two are a problem" - it is "spread ownership of what they touch before one of them leaves". Pair reviews, rotate who owns the risky modules, and write down the decisions that currently live in their heads.
Our Take
Bus factor is one of the few engineering metrics you cannot game.
You can inflate commit counts, lines, or PR volume. You cannot fake the fact that one person is the only one who understands a subsystem. That is why we treat knowledge concentration as a structural risk to manage at the team level - never as a stick to measure an individual with.
Key terms
- Bus factor
- The smallest number of people who would have to leave (be "hit by a bus") before a project loses the majority of its knowledge. Higher is safer.
- Knowledge concentration
- How much of a codebase’s history sits with its most active contributors. High concentration means the team depends heavily on a few people.
- Contributor
- A GitHub account credited with commits to the repository’s default branch. Bot accounts are excluded from this tool’s calculation.
- Default branch
- The primary branch of a repository (usually main or master). GitHub’s contributor counts reflect commits to this branch.
Frequently Asked Questions
It is the smallest number of top contributors whose commits add up to at least half of the repository’s total commits. Contributors are ranked by commit count and counted until the running total crosses 50%.
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See These Features in Action
Detect bus-factor-1 code before it becomes an operational risk.
Find high-churn files and correlate change frequency with ownership.
Interactive graph of review relationships and workload distribution.
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