Simple, transparent pricing

Start free. No credit card required. All endpoints on every tier.

Free
$0/mo
forever
500 requests/month
10 req/min
  • ✓All 6 endpoints
  • ✓Full response schema
  • ✓Address → outlet lookup
  • ✓Library system profiles
  • ✓No credit card
  • ✓No expiry
Get started free
Starter
$19/mo
per month
10,000 requests/month
60 req/min
  • ✓Everything in Free
  • ✓Email support
Get started
Most popular
Pro
$79/mo
per month
50,000 requests/month
120 req/min
  • ✓Everything in Starter
  • ✓Batch endpoint (100 addresses)
  • ✓Webhooks
Get started
Growth
$249/mo
per month
200,000 requests/month
300 req/min
  • ✓Everything in Pro
  • ✓Batch endpoint (500 addresses)
  • ✓99.9% SLA
Get started
Enterprise

Custom volume, raw IMLS data exports, white-label options, dedicated support.

Contact us
Building civic-tech for K-12 or libraries?

Bundle libraryapi.dev with districtapi.dev (school district + school data) for $39/mo combined Starter — perfect for proptech, K-12 SaaS, and civic AI agents. Contact us for the bundle code.

Frequently asked questions

What counts as one request?
Each call to any API endpoint uses one credit — whether it's an outlet lookup, library profile, or state summary. The /v1/health endpoint does not consume credits.
What happens if I exceed my monthly limit?
On the free tier, requests over 500 return a 402 error until your quota resets on the 1st of the month. On paid tiers, requests over your monthly limit return a 402 until the next billing cycle. Upgrade anytime.
How fresh is the data?
Data comes from the IMLS Public Libraries Survey, which is updated annually. We currently serve FY 2023 (released August 2025). New PLS releases are loaded within a week of publication.
What's the source?
Every record traces back to the federal IMLS PLS census — 9,252 public library systems and 17,586 outlets across the 50 states + DC + territories. The data is public domain; we add geocoding, spatial indexing, and a clean REST API.
Can I cancel anytime?
Yes. Cancel from your dashboard at any time. Your plan stays active through the end of the current billing period.
Do you offer a free trial of paid tiers?
The Free tier is permanently free — 500 requests/month with no card. If you outgrow it, you can upgrade and your existing API key keeps working.