How can you tell whether a company sponsors work visas?
Ask what they have already done, because that is the only part written down.
Careers pages are close to useless here. Most say nothing at all, a few say "we are unable to sponsor at this time" and then sponsor, and the rest bury it in a form field you only reach after investing an hour in the application. The information exists, it is simply not where you are looking.
It exists because sponsorship leaves a paper trail. Every H-1B petition an employer files is a filing with a federal agency, and USCIS publishes the aggregate by employer and fiscal year in the H-1B Employer Data Hub. An employer that filed dozens of petitions across several years has demonstrably built the internal machinery: immigration counsel, a budget line, a manager who has done it before.
A careers page tells you what a company is comfortable saying. The petition record tells you what it has actually done.
JobShifu matches those records to the employers behind the jobs in its corpus, so the signal arrives while you are deciding whether to apply, rather than in a screening call three weeks later.
Does a sponsorship history mean they will sponsor you?
No. This is the distinction the whole feature rests on, so it is worth being blunt about.
A petition history is a past fact about an employer. Whether they sponsor you depends on the specific role, the team's budget this quarter, the hiring manager's appetite for the timeline, the cap lottery, and a current policy that may have changed since the last filing. None of that is in the public record, and none of it can be inferred from it.
So the product states the fact and stops. You will see that an employer filed petitions, across which years, and at what rough volume. You will never see JobShifu tell you that a job "will sponsor" or score your odds, because that number would be invented, and inventing numbers is the one thing this product is built not to do.
What you get instead is the ability to spend your evenings on employers where the answer is at least possible.