Thanks.io vs PostGrid: free plans, API access and postcard rates

Thanks.io vs PostGrid: who each is built for

PostGrid's Starter plan is $0 a month and covers up to 500 mailings a month, and its 4x6 postcard is $0.902 at First Class, the faster USPS class, as read on October 24, 2026. Thanks.io's Pay as you go plan is also $0 a month, with a 4x6 postcard at $1.18 (First Class, per its help center) and no minimum.

PostGrid describes a print-and-mail API for letters, postcards and checks, and its pricing page lists no handwriting product. Thanks.io offers a dashboard with CSV upload and digitally rendered handwriting-style script.

Plan fees, limits and per-piece rates

PostGrid pricing, as its page lists it for the USA: Starter is $0 a month with up to 500 mailings, 1 user and 10 templates, and Enterprise is by quote. Prices include printing, processing and postage. Above 500 mailings a month an overage fee applies, and the page gives no amount.

The Thanks.io Pay as you go row is at First Class per its help center and the Business row at Standard Mail. PostGrid's Starter rates are First Class, with printing, processing and postage included.

Standard class rules on each

PostGrid lists Standard class beside First Class: a 6x9 postcard is $0.987 at Standard and $1.023 at First Class. It estimates 5 to 7 business days for First Class and 10 to 15 for Standard, and says Standard class must be marketing in nature and lists business mail as not allowed.

Thanks.io sells Standard Mail, USPS's lower-priced, slower class, only on Business and Professional, so its Pay as you go pieces mail First Class, per its help center. It estimates 5 to 10 business days at First Class and 10 to 20 at Standard Mail.

API, test mode and connectors

Thanks.io includes full REST API access on every plan, Pay as you go included. Its API testing mode accepts orders without producing real mail or charges, and each send endpoint has a matching estimate endpoint that prices an order without placing it. Webhooks, which send events such as delivery to another system, need Business, as do the Zapier and Make connectors. API usage is billed against your account balance.

PostGrid's Starter plan offers API keys, and its page says you can set up a test account and get API documentation.

Who should pick which

Pick PostGrid for developers who mail printed pieces, up to 500 a month, through an API on a $0 plan, including up to 50 checks a month. Pick Thanks.io for handwriting-style mail, notecards and gift cards, a dashboard with CSV upload and no-code sends, and the Business plan from about 120 to 137 4x6 postcards a month. For a developer plan sized by yearly mailings, read Thanks.io vs Lob; PostGrid alternatives and best direct mail API list more.

A practice mailing patient lists should note that Thanks.io says it is not HIPAA compliant and signs no Business Associate Agreements, while PostGrid lists HIPAA compliant mailings on Enterprise. This is not legal advice.

Thanks.io can be opened on Pay as you go at $0 a month, and its API testing mode accepts orders with no real mail or charges.