Comparison

OBD Diagnostics vs Latch

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

Latch

Features
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Did you lock the back door? Is the stove off? Latch ends the second-guessing. Run your lock-up routine before you leave β€” and never wonder again. β€” KEY FEATURES β€” β€’ Multiple location checklists β€” Home, Office, Cabin, or any custom location you add β€’ Starter items included β€” doors, windows, stove, lights, garage, alarm, and more, all ready to edit β€’ Tap-to-check routine β€” check off each item one tap at a time; a completion ring shows your progress live β€’ Visual ring + percentage β€” turns green with a checkmark the moment every item is done β€’ Done button β€” saves today's run to history and clears the list in one tap β€’ Automatic midnight reset β€” every morning starts with a clean slate, no manual reset needed β€’ 14-day history β€” see every lock-up grouped by day, newest first, so you can spot gaps in your routine β€’ Add or delete items β€” customize each checklist to match your real-world routine β€’ Fully offline β€” everything lives on your device, no account, no cloud, no subscription Whether you're securing your home at night, closing the office, or leaving the cabin after a weekend away, Latch keeps your routine tight and your mind at ease. β€” Latch Lockup List PREMIUM β€” Premium unlocks unlimited locations and custom checklists, the full 14-day lock-up history grouped by day, the live completion ring on every routine, and the fully offline experience β€” no account, no ads, no limits. Subscription options: β€’ Weekly β€” $9.99 / week β€’ Yearly β€” $49.99 / year (includes a 3-day free trial) Payment is charged to your Apple Account at confirmation of purchase. Subscriptions renew automatically unless turned off at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours prior to the end of the period. Manage or cancel anytime in your Apple Account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://pnkl26.web.app/privacy-policy

Screenshots

OBD Diagnostics4 screens
Latch3 screens

Verdict

The call

The clearest difference is in-app purchases: Latch at none against OBD Diagnostics's 1. Latch also leads on ads (none vs shown) and update cadence (fortnightly vs monthly). On price and 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

Both are free to download. OBD Diagnostics sells 1 one-off in-app purchase. Latch asks for nothing beyond the download.

UpkeepUpdate frequency

OBD Diagnostics ships an update monthly, Latch fortnightly. The most recent releases landed on October 6, 2026 and October 2, 2026 respectively.

Scorecard4 real differences Β· 2 level
OBD Diagnostics versus Latch: the parameters behind the verdict, then further details
ParameterOBD DiagnosticsLatch
PriceFreeFree
Update frequencyMonthlyFortnightly 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 MB1 MB
Age rating4+4+
DeveloperEJSmithLinh Phan Nhat Khanh

In-app purchases

1 purchases

OBD Diagnostics

One-time1
  • Remove Ads$1.99
None

Latch

No in-app purchases

Questions

Is OBD Diagnostics free?
OBD Diagnostics is free to download, with in-app purchases available.
Is Latch free?
Latch is free to download, with no in-app purchases.
Do OBD Diagnostics or Latch have ads?
OBD Diagnostics shows ads; Latch does not.
Which is updated more often, OBD Diagnostics or Latch?
OBD Diagnostics ships an update monthly, and Latch fortnightly. Most recently, OBD Diagnostics was updated on October 6, 2026 and Latch on October 2, 2026.

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