EasyPost vs Smarty: API comparison

The short answer

EasyPost is a natural integration when shipping objects and label workflows already exist. Smarty is a specialist candidate when US postal analysis and record cleansing are the primary job. Measure verification outcomes separately from successful object creation.

Choose by the task you need to complete
Provider	A good reason to choose it	Important caveat
EasyPost	A shipping workflow already using EasyPost that needs verification results before proceeding to shipment and label operations.	Creating an Address object is not a passed verification. Including verify or verify_strict triggers verification even with false; omit the parameter to skip it. International AVS requires separate enablement.
Smarty	US address operations that need to inspect postal and secondary-unit evidence instead of accepting a normalized string as the only result.	US Street and International are different interfaces and entitlements. A returned candidate must be interpreted using its analysis fields; an empty candidate array is not an application transport error.

Side-by-side differences

EasyPost vs Smarty: documented interfaces, not benchmark scores
Requirement	EasyPost	Smarty
Validation approach	Verification associated with shipping Address objects	US postal-address candidates and analysis
Coverage boundary	Domestic checks; international AVS is separately enabled	US Street endpoint; International is a separate product
Decision signal	verifications success/errors, not Address creation alone	Candidate and DPV-related analysis, not a single global score
Apartment/unit handling	Preserve street2 and inspect correction/splitting behavior	Preserve street2 and interpret secondary-address evidence
Workflow	Create-and-verify or verify an existing Address object	Single-address GET or multi-address POST with server credentials
Cost driver	Account/service entitlement and verification workload	Address lookups, product and licensed features

Pricing: make the units comparable

Billing model and plan checks
Provider	Billing model	What to check
EasyPost	Shipping-account and address-service pricing	Confirm standalone address verification, international AVS and carrier-grade access on your account. Free label allowances or tracking prices are not standalone validation prices.
Smarty	Product-specific lookup subscriptions	Select US or International verification and the required feature/license tier. Batch requests contain multiple addresses; do not calculate price using only the number of HTTP requests.

For 10,000 address checks, include retries and customer edits, not just completed orders. Count input addresses rather than batch HTTP calls. Compare the same country mix and postal evidence; a geocoding credit and a delivery-verification check do not buy the same result.

For a buying decision, calculate total spend divided by accepted outputs at your expected volume. Keep free evaluation access, paid production access, annual commitments and overages separate. We have not measured a cost or speed winner for this pair.

What changes in the integration?

Provider endpoints and input mapping
	EasyPost	Smarty
Method and URL	`POST https://api.easypost.com/v2/addresses`	`GET https://us-street.api.smarty.com/street-address`
Authentication	HTTP Basic auth with the API key as username and an empty password	Server-side auth-id and auth-token; embedded credentials have different restrictions
Inputs	JSON address with street1/street2, city, state, zip and country; include verify or verify_strict deliberately	street, optional street2, city/state/zipcode, candidates and auth credentials; POST supports multiple addresses
Output	Address object plus verifications with success, errors and details; strict verification fails when verification fails.	Candidate array with components, metadata and postal analysis, including DPV-related fields where supplied.

EasyPost: migration check

Omit verify fields entirely when verification is not wanted; false is not an off switch. Distinguish strict API errors from non-strict verification errors before deciding whether a parcel may proceed.

Smarty: migration check

Handle zero, one and multiple candidates explicitly. Preserve leading-zero ZIP codes and separate missing-unit evidence from a street match; batch IDs must map back to original input records.

How to test them fairly

Use provider-approved test fixtures or addresses you have permission to process. Include international formats, accents, rural addresses and unit numbers. Do not generate arbitrary postal addresses or send private customer records without authorization.
Define expected outcomes for known-good records and approved negative cases before the run. Keep unsupported countries and missing evidence separate from invalid addresses.
Measure component correction, unit preservation and false rejection separately. A geocoder's building-level match is not confirmation of postal deliverability or of the person living there.
Record whether the API suggests a correction, confirms a delivery point or merely finds a location. Require customer confirmation when a suggested change could route a parcel elsewhere.
Count billed address checks, repeated checkout attempts, optional geocoding and batch records. Compare latency and cost per accepted decision on the same country mix. No validation result guarantees a successful future delivery.

Record the plan, request settings, time window and acceptance rules with every run. That makes a later result interpretable when a vendor changes a model, source set or pricing tier.

Prefer a common request format?

All Them APIs · Address Validation APIsPOST /api/v1/address-validation/validate

Review the request contract and tell us the coverage you need. Access requires enablement; this endpoint does not execute or bill requests yet.

View endpoint and request access

Sources and review dates

Documentation reviewed October 28, 2026. These are integration and plan comparisons, not measured speed or accuracy rankings. Availability, licensing and prices should be confirmed for the chosen plan.

Corrections: email faizank@docsalot.dev with an official source.