As of 2024-2025, the State Department has opened a limited portal. While not "express" (processing takes 6-8 weeks), it eliminates mailing times. For true express needs, this is not currently a solution, but by late 2025, they may expand to expedited online renewals. Check travel.state.gov for updates.
If you live within 200 miles of a Regional Passport Agency, the in-person appointment is the cheapest "express" option. If you cannot travel, a private courier is your only choice, but you will pay a premium.
Standard passport processing through the U.S. Department of State currently takes between 6 to 8 weeks (or 2 to 3 weeks for expedited service). For many, that is simply too slow. If you need a passport in 72 hours, 24 hours, or even the same day, you need to navigate the complex world of urgent travel passport services.