Ranking updated
Car diagnostics apps in 2026
A phone can read your car’s fault codes once you plug an OBD2 adapter, such as an ELM327, into the car’s diagnostic port. Then Infocar explains the codes in plain levels and clears them, EOBD Facile reads and clears engine and transmission codes, and OBD Fusion adds custom dashboards and fuel economy. Details below.
How we picked: a diagnostics app is only as useful as what it reads through the adapter, so we compared what each app’s own store description says it reads and clears, and what is free and what is paid. Apps with unclear origin are left out.
What you need to diagnose a car with a phone
An OBD2 adapter plugged into the car’s diagnostic port, connected to the phone by Bluetooth or Wi-Fi; EOBD Facile names ELM327 adapters. The app then reads the fault codes the car has stored.
Which app to pick
Infocar inspects ignition, exhaust and electronic systems, sorts fault codes into three levels with descriptions, clears stored codes and analyses driving style; it is free, with some features by subscription or in-app purchase. EOBD Facile reads and clears engine and transmission fault codes, including manufacturer-specific ones. OBD Fusion reads codes, clears the check engine light, estimates fuel economy and builds custom dashboards.
| App | Best for | Platforms | Price | Needs adapter |
|---|---|---|---|---|
| InfocarApp StoreGoogle Play | fault codes explained, driving analysis | iOS, Android | free; some features by subscription | yes, OBD2 |
| EOBD FacileApp StoreGoogle Play | reading and clearing engine codes | iOS, Android | free to download | yes, ELM327 |
| OBD FusionApp StoreGoogle Play | dashboards, codes and fuel economy | iOS, Android | paid app | yes, OBD2 |
Frequently asked questions
Can I diagnose my car with just a phone?
You also need an OBD2 adapter, such as an ELM327, plugged into the car’s diagnostic port; the app reads the fault codes through it.
Is there a free car diagnostics app?
Infocar is free, with some features by subscription or in-app purchase, and EOBD Facile is free to download; OBD Fusion is a paid app.