React Diff Viewer: Is the npm Package Still Safe to Use?

The original react-diff-viewer npm package works, but it has gone years without a release and no longer keeps pace with modern React, so for new projects the maintained fork react-diff-viewer-continued is the safer choice. If you already depend on the original, it is not an emergency, but it is exactly the kind of quietly stale dependency that turns into a problem later.

React diff viewer is a small, genuinely useful component: it renders a side-by-side or inline comparison of two strings, built on top of the diff library, with syntax highlighting and word-level highlighting. The functionality is not the issue. Maintenance is.

The maintenance status, plainly

The original package on npm was last published around six years ago. In open-source terms that is a long time to sit still, and the practical effects show up quickly:

• React compatibility drift. React 18 changed how the root API and strict mode behave. The original package predates that, and the project's issue tracker has a long-standing React 18 request that never landed in a release. Teams on React 18 or 19 hit peer-dependency warnings and, occasionally, runtime quirks.
• Frozen dependencies. A package that never republishes never bumps its own transitive dependencies. Any advisory affecting those deps stays unaddressed upstream.
• No security response path. If a vulnerability were reported against an abandoned package, there is nobody shipping a fix. You would be patching it yourself or forking.

None of this means the package is currently exploitable — a diff renderer has a small attack surface, mostly around how it handles untrusted input for display. But "no known CVE today" and "will be patched if one appears" are different guarantees, and only the second one actually protects you.

Meet react-diff-viewer-continued

react-diff-viewer-continued is a community fork (maintained by Aeolun) that picks up where the original left off. At the time of writing its latest release is in the 4.x line, published recently, with active issues and merges. It keeps the same friendly API while addressing the things the original could not:

• React 18 support and updated peer dependencies.
• Refreshed build tooling and TypeScript types.
• Ongoing bug fixes and dependency updates.

Migration is usually close to a drop-in swap:

npm uninstall react-diff-viewer
npm install react-diff-viewer-continued

// The import path changes; the component API is largely the same
import ReactDiffViewer from 'react-diff-viewer-continued';

function Changes({ before, after }) {
  return <ReactDiffViewer oldValue={before} newValue={after} splitView />;
}

Check the fork's changelog for the handful of prop and styling adjustments between the major versions before you upgrade in bulk. Because the fork advanced its major version, there are a few breaking changes relative to the original 3.x line.

The broader lesson: unmaintained is a risk class

The react-diff-viewer situation is common. A tiny, well-liked utility gets written, works perfectly, and the author moves on. Nothing breaks, so nobody notices — until a security advisory or a framework upgrade forces the issue, and now you are auditing a dependency you had forgotten was even there.

Two signals are worth tracking for every direct dependency:

1. Last publish date. A package that has not shipped in over two years, especially in a fast-moving ecosystem like React, should be on a watchlist.
2. Open-but-unmerged issues around compatibility. A pile of "does this support React 18?" issues with no maintainer reply is a strong tell.

You do not need to rip out every stale package immediately. You do need to know which ones they are. An SCA tool such as Safeguard can flag dependencies that are unmaintained or that have known-vulnerable transitive packages, which is how most teams find the react-diff-viewer-shaped risks hiding in their lockfiles.

How to evaluate any React component before adopting it

Before you add a rendering component like a diff viewer, spend five minutes on due diligence:

• npm and GitHub activity — recent commits, recent releases, responsive maintainers.
• Weekly download trend — a healthy fork like react-diff-viewer-continued shows steady adoption.
• Peer-dependency ranges — does it declare support for your React version?
• Bundle size and dependency count — a diff viewer should be light; watch for surprise heavyweight transitive deps.
• How it handles input — for anything that renders user-supplied text, confirm output is escaped and not injected as raw HTML.

Our academy has a longer walkthrough on vetting open-source dependencies before they enter your build.

FAQ

Is react-diff-viewer deprecated?

It is not formally marked deprecated on npm, but it is effectively unmaintained — no releases in years and an open React 18 compatibility request. Treat it as legacy and prefer the maintained fork.

What is the difference between react-diff-viewer and react-diff-viewer-continued?

react-diff-viewer-continued is a fork of the original that continues active maintenance: React 18 support, updated dependencies, and ongoing fixes. The core API and appearance are very similar, so migration is usually straightforward.

Does react-diff-viewer have a known CVE?

There is no widely publicized CVE against the component at the time of writing. The risk is not a current exploit but the absence of a maintainer to respond if one is disclosed, plus its transitive dependencies never being updated.

Is the migration to the continued fork breaking?

Mostly no, but the fork advanced its major version, so review its changelog for a few prop and styling changes before upgrading across a large codebase.