# Smarty vs PostGrid Address Verification: which do AI models recommend for address verification, October 2026

GTM AI Recommendation Index, October 2026 Edition, Address verification tools. Nine of fourteen models named Smarty first on the direct prompt; one named PostGrid Address Verification. Page: https://gtm-ai-index.com/gtm-data/address-verification/smarty-vs-postgrid-address-verification/

| | First-choice share | Rank | Negative rate | Labels | Models naming it |
|---|---|---|---|---|---|
| Smarty | 47% | #1 of 7 | 0% | 61 | 14 of 14 |
| PostGrid Address Verification | 8% | #2 of 7 | 3% | 39 | 13 of 14 |

## The direct prompt, model by model

- Perplexity Sonar: smarty first (first choices: Smarty) (alternatives: Loqate, Melissa, PostGrid Address Verification)
- Grok 4.1 Fast: smarty first (first choices: Smarty) (alternatives: Melissa, PostGrid Address Verification)
- DeepSeek V4 Flash: smarty first (first choices: Smarty) (alternatives: Loqate, Melissa, PostGrid Address Verification)
- Qwen 3.7 Flash: smarty first (first choices: Smarty) (alternatives: Loqate, Melissa)
- Kimi K2: smarty first (first choices: Smarty) (alternatives: Loqate, Melissa Global Address Verification)
- GLM 4.7 FlashX: smarty first (first choices: Smarty) (alternatives: Experian Address Validation, Melissa, PostGrid Address Verification)
- MiniMax M2.5: smarty first (first choices: Smarty) (alternatives: Melissa, PostGrid Address Verification)
- GPT-6 Luna: smarty first (first choices: Smarty) (alternatives: Lob, Loqate, Melissa)
- Muse Glimmer 30B: smarty first (first choices: Loqate by gbg, Smarty) (alternatives: Melissa Address Verification)
- Claude Haiku 4.5: postgrid address verification first (first choices: PostGrid Address Verification) (alternatives: Informatica Data as a Service, Melissa Address Verification, Smarty)
- GPT-5.4 mini: neither first, one named (first choices: Melissa Global Address Verification) (alternatives: Experian Address Verification, PostGrid Address Verification, Smarty)
- Gemini 3.5 Flash: neither first, one named (first choices: Loqate) (alternatives: Lob, Melissa, PostGrid Address Verification, Smarty)
- Mistral Small: neither first, one named (first choices: Experian Address Validation, Melissa Global Address Verification) (alternatives: Loqate, PostGrid Address Verification)
- Llama 4 Maverick: neither named

## What the models said about Smarty

- "Smarty (formerly SmartyStreets) is a fast and highly scalable address verification API used heavily in high-volume e-commerce and logistics environments." (Muse Glimmer 30B, comparative prompt, first choice)
- "I would recommend Smarty if your volume is mostly U.S. addresses and you want a developer-friendly API with strong validation tooling" (Perplexity Sonar, paraphrase prompt, first choice)
- "### 1. Smarty (formerly SmartyStreets)
- Best for: US address verification, developer-friendly implementations, e-commerce checkout" (Kimi K2, comparative prompt, first choice)

## What the models said about PostGrid Address Verification

- "PostGrid has been flagged in independent reviews for specific reliability issues." (GLM 4.7 FlashX, negative prompt, soft negative)
- "PostGrid is a strong option for SaaS and B2B teams because it combines address verification, autocomplete, bulk list cleanup, international coverage, API access, and dashboard-based workflows in one platform." (Claude Haiku 4.5, direct prompt, first choice)
- "PostGrid's pay-as-you-go model allows you to get started without investing anything, which is ideal for companies with truly limited budgets" (Claude Haiku 4.5, budget prompt, first choice)
- "Best budget option (US/Canada): PostGrid - $20/mo for 2,000 lookups" (Muse Glimmer 30B, budget prompt, first choice)

Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category. Comparisons are drawn for the top eight products in each category. Published under CC BY 4.0; the output is the models' output, and nothing here is a recommendation by the index.