What Are the Current igraph Releases and Versioning Status?

As of the latest news on igraph.org, the C/igraph core library has reached 1.0.1 (released Dec 26th, 2025), the first bugfix release of the 1.0 series. The 1.0 line began with C/igraph 1.0.0 on Sep 20th, 2025, which introduced a more consistent and predictable API and an official versioning policy. The older 0.10.x branch is now closed out, with 0.10.17 described as the last planned release of the 0.x series. Language bindings move on their own schedules: the igraph R package has crossed the 2.0 threshold, and python-igraph continues to ship updates (0.11.8 and 0.11.6 appear in the news list).

Release status at a glance

What changed in 1.0.0

The 1.0.0 announcement frames the release as the culmination of nearly twenty years of development, focused on giving users and downstream maintainers an interface they can rely on. The listed highlights:

• A more consistent and more predictable API.
• An explicit versioning policy, documented in VERSIONING.md.
• Several random graph generators, including the Erdős–Rényi generators, can now produce graphs with multi-edges.
• Functions that can generate large numbers of results (cliques, cycles, etc.) gained options to limit the number of returned results or return a single result only.
• New functionality for generating several kinds of spatial networks.

Because 1.0 required API-breaking changes, the 0.10.17 announcement warns that code written against 0.x may need adjustment. If you maintain a project pinned to 0.10, that is the branch to stay on until you can absorb the breaking changes.

How to read the version numbers

The project now separates the C core from its language packages, and each carries its own version. A 1.0.x C release does not imply an R or Python package with the same number — the R package is on 2.x and python-igraph on 0.11.x. When checking compatibility, look at the release notes for the specific binding you use rather than assuming version parity with the C library.

The 1.0.1 notes are described as bug fixes and documentation improvements only, so it is a low-risk upgrade within the 1.0 series. Source for all releases is available from the GitHub releases page linked in each announcement.

Where to verify current versions

The site's news section is the authoritative place to confirm what is current: it lists C/igraph 1.0.1, 1.0.0, and 0.10.17 alongside python-igraph and R package announcements, plus a post titled "Setting up igraph for success in the next decade." For the exact changelog of any release, follow the "More →" link in the corresponding news item, which points to the GitHub release summary.