To understand why pull requests exist, picture what would happen without them.

The problem: unreviewed changes going straight into the main project

Without any process in place, any team member could make a change and immediately have it become part of the official, shared version of the project — no second opinion, no safety check, no discussion. On a solo hobby project that might be fine, but on a team of any size, this quickly becomes risky. Bugs slip through, inconsistent styles pile up, and nobody else on the team necessarily knows a change happened until something breaks.

The solution: a formal request to merge

A pull request, often abbreviated “PR,” is a formal request asking the project’s maintainers to take a set of changes from one line of work and merge them into another — almost always from a separate branch into the project’s main branch. Crucially, a pull request doesn’t merge anything by itself. It opens a structured space for discussion, automated checks, and human review to happen first, and the actual merge only occurs once that process is satisfied.

A pull request doesn’t happen in isolation — it sits at a specific, predictable point in a broader everyday workflow.

The typical flow starts with a developer creating a separate branch to work on a specific change, isolated from the main project. They make their edits and commits on that branch, and once the work feels ready, they open a pull request asking for it to be merged back into the main branch. From there, the pull request becomes a shared space where teammates can leave comments, request changes, run automated checks, and eventually approve the work before it’s merged.

flowchart LR
    A["Create a separate branch"] --> B["Make changes and commits"]
    B --> C["Open a pull request"]
    C --> D["Review, discuss, and request changes"]
    D --> E{Approved?}
    E -- Yes --> F["Merge into main branch"]
    E -- No, needs work --> B
    style A fill:#fafafa,stroke:#e5e5e5
    style C fill:#fef2f2,stroke:#dc2626
    style F fill:#111111,stroke:#111111,color:#ffffff
        

Opening a pull request triggers a specific, structured set of things on a hosting platform.

Every pull request is built from a fixed set of parts, no matter how big or small the change is.

Reviewing is where most of the actual value of a pull request comes from.

During review, teammates read through the proposed change and leave comments — pointing out bugs, suggesting cleaner approaches, asking clarifying questions, or simply approving the work as-is. This conversation happens directly alongside the code, often attached to specific lines, so feedback is precise and easy to follow rather than scattered across a separate chat.

Typical review outcomes

A reviewer generally responds in one of a few ways: approving the change as ready to merge, requesting specific changes before it can be approved, or simply leaving comments without blocking the change outright. Many teams require at least one approval, and sometimes several, before a pull request is allowed to be merged at all.

Human review is powerful, but most modern teams pair it with automated checks that run on every pull request.

When a pull request is opened or updated, automated systems can automatically run a project’s test suite, check code formatting, scan for known security issues, or verify the project still builds correctly. The results of these checks are displayed directly on the pull request, usually as a simple pass or fail indicator, giving both the author and reviewers immediate, objective feedback before a human even needs to look closely.

Once a pull request is approved and checks have passed, it’s ready for the final step.

Merging is the moment the changes from the source branch are actually combined into the target branch, becoming a permanent part of that branch’s history. Most hosting platforms offer a few different ways to perform this merge, each producing a slightly different shape of history, though the end result is always the same: the target branch now contains the proposed changes.

After a merge, the pull request itself doesn’t disappear — it’s marked as merged and remains as a permanent, searchable record of what was discussed, reviewed, and ultimately decided, which is often just as valuable as the code change itself.

These are the most frequent stumbling blocks people run into when they first start opening pull requests.

A handful of consistent habits make pull requests faster to review and far more pleasant for everyone involved.

Pull requests are one of the most widely relied-upon practices across the entire software industry.

Large open-source projects depend on pull requests to manage contributions from thousands of independent developers who have never met each other, using the process as a trusted, structured gate before any outside change becomes part of the official project. Inside companies, pull requests serve the same purpose on a smaller scale, acting as the standard checkpoint every engineer’s work passes through before it reaches production.

No. A commit is a single saved snapshot of changes. A pull request is a broader request, usually containing one or more commits, asking for those changes to be reviewed and merged into another branch.

Yes. Adding new commits to the source branch automatically updates the open pull request, letting you respond to feedback without needing to open a brand-new one.

It can simply be closed without merging, and the target branch is completely unaffected — as if the proposed change had never been suggested, though the discussion typically remains visible for future reference.

No. Even individuals working alone commonly use pull requests as a personal checkpoint, taking advantage of automated checks and a clear record of what changed and why, even without another human reviewer.

No. Some platforms use the term “merge request” instead, referring to the same underlying idea: a formal request to merge one branch’s changes into another after review.

Yes. A maintainer can close a pull request without merging it if the change isn’t wanted, though the record of the request and its discussion typically stays visible in the project’s history.

A pull request is the formal checkpoint that stands between a proposed change and the official, shared version of a project. Rather than letting changes flow directly into the main branch, it opens a structured space for review, discussion, and automated checks, ensuring that what eventually gets merged has been genuinely evaluated rather than simply assumed to be correct. Far more than just a technical mechanism, a pull request is a communication tool — a permanent, searchable record of what changed, why it changed, and what the team collectively decided about it, which is often just as valuable to a project’s long-term health as the code itself.