About GTFS Guru
GTFS Guru is a free, open-source validator for GTFS Schedule feeds, written in Rust and maintained by Abasis.AI. It reimplements the rules of MobilityData's canonical gtfs-validator so the same checks can run in a browser tab, on the command line, from Python, in CI and inside AI assistants, without a Java runtime.
What it is
The validator runs 110 checks and reports 191 notice codes. The codes and the report layout follow the canonical validator, so a report from either tool reads the same way. The rule sets are close but not identical, and the compatibility page lists the GTFS reference revision and canonical release this build answers for, along with every known difference.
MobilityData's validator remains the reference implementation. GTFS Guru is an independent project that tracks it.
Who builds it
GTFS Guru is built and maintained by Igor Akimov at Abasis.AI, who wrote the Rust validator, the parity harnesses and the notice guides on this site. Changes go through public pull requests on GitHub.
How it is kept correct
Golden suite. Small controlled feeds whose reports are pinned byte for byte, so any change in output is caught in review.
Real-world parity. Twelve pinned MobilityData datasets covering flexible services, Fares v2 and pathways, from 31 KiB to 229 MiB unpacked. They are checked on every commit and compared against the canonical Java validator before every release.
Spec watch. The GTFS reference in google/transit and the canonical validator's releases are tracked, so a new field, enum value or rule shows up as a reviewed change instead of a silent gap.
The method and the commands to reproduce the speed figures are in the benchmarks.
Your data
A feed you pick from your device is validated in your browser and never uploaded. Validating by URL can pass the archive through our server for that one request. The privacy policy describes both paths.
License and contact
The code is Apache 2.0 and lives on GitHub, where bug reports and contributions are welcome. For anything else, write to gtfs@abasis.ai.