Comparison

OBD Diagnostics vs RevDash

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

Head to head
About

OBD Diagnostics

Features
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OBD Diagnostics turns your iPhone into a powerful real-time vehicle data scanner, dashboard, session recorder, and AI analysis tool. Connect to supported Bluetooth OBD-II adapters, including Veepeak and compatible ELM327-style adapters, to read live vehicle data directly from your car. View key engine metrics, track driving sessions, graph sensor data, and send your recorded measurements to AI for personalized analysis based on your vehicle’s make, model, year, and engine. Whether you are troubleshooting a check engine light, monitoring engine performance, reviewing fuel trims, checking battery voltage, or learning how your vehicle behaves over time, OBD Diagnostics helps make your car’s data easier to understand. **Real-Time OBD-II Dashboard** Monitor live data from your vehicle with a clean, easy-to-read dashboard. View supported OBD-II PIDs such as: Engine RPM Vehicle speed Coolant temperature Battery voltage Engine load Short-term fuel trim Long-term fuel trim Oxygen sensor readings Fuel level Additional supported sensor values Large gauges, live value cards, and quick-access charts help you focus on the vehicle data that matters most. CarPlay support with live data. Shortcut actions to automatically connect and start as well as disconnect and stop analysis. **Interactive Graphs** Visualize your vehicle’s live data with real-time graphs. Select up to 10 dashboard PIDs and track changing values over the last 60 seconds. Great for reviewing RPM changes, coolant temperature rise, fuel trim movement, voltage behavior, speed changes, oxygen sensor activity, and engine load patterns. **Session Recording and History** Record OBD-II sessions and review them later. Each session can include duration, sample count, vehicle information, VIN when available, make, model, year, engine, battery voltage, and min/max/average stats for recorded metrics. Use session history to compare drives, spot changing patterns, and better understand intermittent vehicle issues. **AI Vehicle Analysis** Send recorded session logs to AI for a plain-language review of your vehicle data. OBD Diagnostics can analyze readings using your vehicle’s make, model, year, and engine to help explain performance trends and possible areas to watch. AI analysis can help summarize coolant temperature, RPM, speed, battery voltage, oxygen sensor readings, engine load, fuel trims, and other supported metrics. Choose from multiple AI provider options, including Apple on-device AI where available, OpenAI, Gemini, Claude, xAI, or a custom URL. AI Analysis should NOT be considered a replacement to a professional automotive expert. Please use the data as a means to provide a rudimentory analysis of your vehicle. **Demo Mode** Explore the app without an adapter using Demo Mode. Simulate vehicle data, view dashboards, test graphs, record sessions, and preview AI analysis workflows before connecting to a real car. **Built for Drivers and DIY Mechanics** OBD Diagnostics is useful for car owners, DIY mechanics, used car shoppers, fleet users, and anyone who wants better visibility into vehicle health and performance. **Key Features** Real-time OBD-II Bluetooth data Veepeak and ELM327-style adapter support Live RPM and speed gauges Custom dashboard PID selection Interactive vehicle graphs Session recording and history Vehicle info and VIN capture when available Min, max, and average metric summaries AI-powered session analysis On-device AI option where supported Custom AI provider support Demo Mode for offline testing Clean dark-mode iPhone interface OBD Diagnostics combines live OBD-II data, Bluetooth scanner support, real-time charts, session tracking, and AI-powered vehicle analysis into one simple app for understanding your car’s performance and health.

About

RevDash

Read full description

RevDash turns your iPhone into a premium automotive dashboard. Connect a compatible ELM327 BLE 4.0 OBD-II adapter to your vehicle and get real-time visibility into everything your car is doing β€” engine RPM, coolant temperature, vehicle speed, fuel consumption, and more. LIVE DASHBOARD Monitor your vehicle's vital signs in real time with a clean, instrument-cluster-inspired interface. Gauges update live as you drive, with color-coded indicators that alert you before a problem becomes serious. AUTOMATIC TRIP RECORDING RevDash detects when your engine starts and stops, automatically logging every trip without you lifting a finger. Review your full trip history with distance, duration, fuel consumed, and route maps. DRIVING INSIGHTS VIA APPLE INTELLIGENCE Get weekly summaries and pattern analysis powered by Apple Intelligence. Understand your driving habits, journey profiles, and fuel economy trends over time. DIAGNOSTIC TROUBLE CODES Read and clear OBD-II diagnostic codes directly from the app. RevDash shows plain-language descriptions per vehicle so you know exactly what your car is telling you. WIDGETS & LIVE ACTIVITIES Keep your last trip stats and active trip progress visible from your screen and Dynamic Island β€” no need to open the app. MULTI-VEHICLE SUPPORT Manage multiple vehicles from a single account. Each vehicle maintains its own trip history, diagnostic records, and settings. DESIGNED FOR DRIVERS Dark-first UI built for readability at night and in sunlight. No subscriptions. No ads. No data collection. Your driving data stays on your device. REQUIREMENTS - Compatible ELM327 BLE 4.0 OBD-II Bluetooth adapter - Vehicle with OBD-II port (most cars manufactured after 1996) - iPhone with Bluetooth and Location enabled

Screenshots

OBD Diagnostics4 screens
RevDash4 screens

Verdict

The call

The clearest difference is price: OBD Diagnostics at Free against RevDash's $1.99. RevDash's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

OBD Diagnostics is free to download; RevDash costs $1.99 up front. OBD Diagnostics sells 1 one-off in-app purchase. RevDash asks for nothing beyond the download.

UpkeepUpdate frequency

OBD Diagnostics ships an update monthly, RevDash every 3 days. The most recent releases landed on September 18, 2026 and September 4, 2026 respectively.

Scorecard5 real differences Β· 1 level
OBD Diagnostics versus RevDash: the parameters behind the verdict, then further details
ParameterOBD DiagnosticsRevDash
PriceFree β€” better$1.99
Update frequencyMonthlyEvery 3 days β€” better
AdsYesNo β€” better
In-app purchasesYesNo β€” better
DevicesiPhone, iPad β€” betteriPhone
Requires iOS26.217.0 β€” better
Further details β€” not scored
Size23 MB14 MB
Age rating4+4+
DeveloperEJSmithJoshua Figueroa

In-app purchases

1 purchases

OBD Diagnostics

One-time1
  • Remove Ads$1.99
None

RevDash

No in-app purchases

Questions

Is OBD Diagnostics free?
OBD Diagnostics is free to download, with in-app purchases available.
Is RevDash free?
RevDash costs $1.99, with no in-app purchases.
Do OBD Diagnostics or RevDash have ads?
OBD Diagnostics shows ads; RevDash does not.
Which is updated more often, OBD Diagnostics or RevDash?
OBD Diagnostics ships an update monthly, and RevDash every 3 days. Most recently, OBD Diagnostics was updated on September 18, 2026 and RevDash on September 4, 2026.

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