Comparison

OBD2 Scanner | OBD Auto Doctor vs OBD Compass

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

OBD2 Scanner | OBD Auto Doctor

Transform your iPhone into a car diagnostic tool. Read and clear engine trouble codes, monitor live engine data, and check emissions readiness with a compatible OBD2 dongle.

Highlights
  • Read and clear diagnostic trouble codes (DTCs)
  • Monitor live engine data
  • Check emissions readiness
  • View freeze-frame data
  • Create custom sensor dashboards
  • Works with compatible OBD2 dongles
Read full description

Turn your iPhone into a powerful OBD2 car scanner and diagnose your vehicle yourself. Check why your Check Engine Light is on, read and clear diagnostic trouble codes, monitor live engine data, and check emissions readiness — all from your iPhone or iPad with a compatible OBD2 dongle. CHECK YOUR CHECK ENGINE LIGHT Don't guess what's wrong with your car. OBD Auto Doctor reads diagnostic trouble codes from your vehicle and provides detailed information to help you understand what they mean. • Read diagnostic trouble codes (DTCs) • Clear Check Engine Light codes • View detailed code descriptions • Read freeze-frame data MONITOR YOUR CAR IN REAL TIME See what's happening while your engine is running with live OBD2 data. • Engine RPM and vehicle speed • Coolant temperature • Fuel system and fuel trim data • Throttle position • Intake air and engine load • Oxygen sensor data • And many other vehicle parameters Create your own dashboard and choose exactly which sensors you want to monitor. CHECK EMISSIONS READINESS Preparing for an emissions or vehicle inspection? Check your vehicle's readiness monitors and see whether your car's emissions systems have completed their tests. WORKS WITH OBD2 DONGLES Connect OBD Auto Doctor to your vehicle using a compatible Bluetooth, Wi-Fi or Bluetooth Low Energy (BLE) OBD2 dongle. Compatible dongles include many ELM327-based adapters, OBDLink, Vgate, Linker, Veepeak and other compatible OBD2 interfaces. Please note: An OBD2 dongle is required to connect the app to your vehicle. Dongle compatibility and available features depend on your vehicle. MORE THAN JUST A CODE READER OBD Auto Doctor gives you access to the information your car's onboard diagnostic system makes available. • Read vehicle information • Monitor fuel consumption • View and record live sensor data • Read diagnostic trouble codes • Clear diagnostic trouble codes • Check emissions readiness • View freeze-frame data • Monitor vehicle performance Whether you're trying to understand a Check Engine Light, preparing your car for inspection, monitoring your engine, or simply want to know more about your vehicle, OBD Auto Doctor puts professional-style OBD2 diagnostics in your pocket. Download OBD Auto Doctor and start diagnosing your car today. SUBSCRIPTION OBD Auto Doctor offers optional subscriptions that unlock additional features. Terms of Use: https://www.obdautodoctor.com/terms

About

OBD Compass

Features
Read full description

The Bluetooth OBDII scan tool is loaded with essential features such as full OBDII functionality. Key Features: 1. Vehicle health check, read vehicle faults. 2. Various visual data such as numerical values, waveforms, and dials. 3. n-depth analysis of fault codes, including causes of generation, potential impacts of fault codes on vehicles, maintenance suggestions, and estimated costs, etc. 4. Maintenance records and reminders. 5. Community and Knowledge Base.

Screenshots

OBD2 Scanner | OBD Auto Doctor4 screens
OBD Compass3 screens

Verdict

The call

The clearest difference is in-app purchases: OBD Compass at none against OBD2 Scanner | OBD Auto Doctor's 9. OBD Compass also leads on iOS requirement (13.0 vs 17.0). On price, update cadence, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. OBD2 Scanner | OBD Auto Doctor sells 9 in-app purchases, starting at $4.99 per month. OBD Compass asks for nothing beyond the download.

UpkeepUpdate frequency

OBD2 Scanner | OBD Auto Doctor ships an update every 3 weeks, OBD Compass monthly. The most recent releases landed on November 9, 2026 and October 31, 2026 respectively.

Scorecard2 real differences · 8 level
OBD2 Scanner | OBD Auto Doctor versus OBD Compass: the parameters behind the verdict, then further details
ParameterOBD2 Scanner | OBD Auto DoctorOBD Compass
PriceFreeFree
Rating4.4 (6.2K ratings) — better—
Positive reviews30.4% of reviews—
Number of ratings6.2K — better—
Update frequencyEvery 3 weeks — betterMonthly
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.013.0 — better
Further details — not scored
Size19 MB25 MB
Age rating4+4+
DeveloperCreosysHK TOPDON TECHNOLOGY Co., LIMITED

Bugs and requests

OBD2 Scanner | OBD Auto Doctor

Reported bugs

4 issues
  • App crashes on launch
  • Fails to detect existing fault codes
  • Subscription issues and inability to cancel
  • Incompatible with certain OBD2 adapters

Requested features

6 requests
  • Add support for more vehicle makes and models
  • Improve Bluetooth/WiFi connectivity
  • Provide more detailed diagnostic information
  • Allow clearing of error codes without subscription
  • Add live data dashboards and graphs
Show 1 more
  • Integrate with vehicle maintenance scheduling

OBD Compass

Not enough reviews yet to summarise bugs or requests.

In-app purchases

9 purchases

OBD2 Scanner | OBD Auto Doctor

Subscriptions8
  • Monthly (legacy)$4.991 Month
  • Personal, monthly$4.991 Month
  • Premium, monthly$5.991 Month
Show 5 more
  • Professional, monthly$6.991 Month
  • Yearly (legacy)$23.991 Year
  • Personal, yearly$23.991 Year
  • Professional, yearly$29.991 Year
  • Premium, annual3 Days trial$29.991 Year
One-time1
  • OBD Auto Doctor Pro (legacy)$29.99
None

OBD Compass

No in-app purchases

Questions

Is OBD2 Scanner | OBD Auto Doctor free?
OBD2 Scanner | OBD Auto Doctor is free to download, with in-app purchases available.
Is OBD Compass free?
OBD Compass is free to download, with no in-app purchases.
Do OBD2 Scanner | OBD Auto Doctor or OBD Compass have ads?
Neither OBD2 Scanner | OBD Auto Doctor nor OBD Compass shows ads.
Which is updated more often, OBD2 Scanner | OBD Auto Doctor or OBD Compass?
OBD2 Scanner | OBD Auto Doctor ships an update every 3 weeks, and OBD Compass monthly. Most recently, OBD2 Scanner | OBD Auto Doctor was updated on November 9, 2026 and OBD Compass on October 31, 2026.

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