Comparison

Papertrail Auto vs DiagonalOBDII

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

Head to head
About

Papertrail Auto

This app helps car owners meticulously document their vehicles, from basic specs to maintenance history and memorable journeys. It offers AI-powered input, secure cloud storage, and the ability to generate presentations or transfer ownership records.

Highlights
  • Detailed vehicle documentation
  • AI-powered data input
  • Photo and description uploads
  • Create car 'Stories'
  • Generate PDF/web presentations
  • Transfer ownership records
  • Encrypted cloud storage
Features
Read full description

Are you a restorer, DIYer, or simply a caring owner of cars? This Winter, up your organization game with Papertrail! We aim to be the #1 platform for vehicle documentation and logging. Store pictures and details. Secure your vehicle's legacy in our encrypted cloud. Access them from any device anywhere. Present or transfer them to others. It's simply amazing! Key Features: Detailed Documentation: Keep track of everything from basic info like make and model to intricate details like modifications and maintenance. Our AI-powered input makes logging details quick and accurate. Add in your favorite photos to make each entry more personal! Upload photos, descriptions, and cost. Great for big car restoration projects and day-to-day maintenance. Tell Your Car's Story: Document your memorable trips, restoration projects, or car shows in 'Stories', adding a personal touch to your car's history. Share your adventures, road trips, or projects. Present Your Car: Generate a webpage or a PDF presentation of your car's records and stories - ideal for sharing with others or when listing your car for sale. Showcase your journey and history with stunning presentations. Transfer History: Selling your ride? Our easy-to-use interface lets you transfer all the records and stories to the new owner, keeping the legacy intact. Ensure the new owner appreciates the legacy and care. Private & Secure: Your records are private until you decide to share them. And with our cloud-based storage, you won't lose your records even if you lose your phone. Rest easy knowing that eveyrthing is stored in the cloud. Why Choose Papertrail? - Comprehensive Vehicle Log: Capture every detail from specs to special moments of your Lamborghini or classic cars. - AI-Powered Input: Quickly and accurately log details with our advanced AI technology. - Immersive Storytelling: Create a living document of your car’s adventures. - Effortless Sharing: Showcase your car’s history with stunning presentations. - Seamless Ownership Transfers: Ensure continuity of your car’s legacy. - Robust Security: Keep your data safe with private and secure cloud storage. - At Papertrail, we're not just about storing data; we're about preserving the passion and pride of car ownership. Become a part of a growing community of car lovers who understand the importance of documenting and celebrating their automotive journeys. Download Papertrail today and start telling your car's story! Some brands on the platform: Chevrolet, Ford, BMW, Toyota, Honda, Porsche, Mercedes, Audi, Tesla, Lamborghini. Terms of Use (EULA): https://www.papertrail.tech/policies/terms

About

DiagonalOBDII

This app helps mechanics perform vehicle drive cycles more efficiently. It provides real-time monitoring of emissions monitors and diagnostic trouble codes (DTCs), offering clear guidance and instant explanations to ensure vehicles pass inspection quickly and accurately.

Highlights
  • Live drive cycle monitoring
  • Immediate diagnostic trouble code (DTC) identification
  • Real-time emissions monitor status
  • Precise drive cycle parameter guidance
  • Professional, easy-to-navigate dashboard
  • Instant code explanations
Read full description

Diagonal is designed specifically for mechanics who want to simplify and speed up vehicle drive cycles. Instantly track emissions monitors and diagnostic trouble codes (DTCs) live, ensuring accurate diagnostics and rapid vehicle readiness for inspection. Key Features: -Live Drive Cycle Monitoring: Clearly see the real-time status of emissions monitors as they run, complete, or require further action during your drive. -Immediate Diagnostics: Quickly identify and address active trouble codes (DTCs) as they appear, eliminating uncertainty during drive cycles. -Efficiency and Accuracy: Avoid unnecessary repeat drive cycles by verifying real-time monitor completion, ensuring vehicles pass inspection on the first try. -Precise Drive Cycle Guidance: Monitor essential drive cycle parameters such as speed, RPM, engine temperature, and throttle position to meet exact diagnostic requirements. -Professional Dashboard: Access all critical information quickly through a clear, easy-to-navigate interface tailored for automotive professionals. -Instant Code Explanations: Quickly interpret trouble codes with straightforward, mechanic-friendly explanations. Why Mechanics Trust Diagonal: -Saves Valuable Time: Complete diagnostic drive cycles accurately the first time. -Faster Inspections: Immediately identify vehicle readiness to streamline your workflow. -Reduces Diagnostic Uncertainty: Clear, actionable data presented in real-time. -Diagonal empowers professional technicians with the tools to perform diagnostics faster and more efficiently than ever before. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://diagonal-d070c.web.app/privacy.html

Screenshots

Papertrail Auto4 screens
DiagonalOBDII4 screens

Verdict

The call

The clearest difference is review sentiment: Papertrail Auto at 83% against DiagonalOBDII's 0%. Papertrail Auto also leads on ratings volume (24 vs 1) and update cadence (every 4 days vs every 2 weeks). DiagonalOBDII's advantage is rating (5.0 vs 4.8). On price, ads, in-app purchases and monetization model 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. Papertrail Auto sells 1 in-app purchase, starting at $15.99 per month and DiagonalOBDII sells 4 in-app purchases, starting at $12.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

DiagonalOBDII holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Papertrail Auto has 24 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 83% of Papertrail Auto's written reviews are positive against 0% of DiagonalOBDII's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Papertrail Auto ships an update every 4 days, DiagonalOBDII every 2 weeks. The most recent releases landed on October 9, 2026 and October 5, 2026 respectively.

Scorecard6 real differences · 4 level
Papertrail Auto versus DiagonalOBDII: the parameters behind the verdict, then further details
ParameterPapertrail AutoDiagonalOBDII
PriceFreeFree
Rating4.8 (24 ratings)5.0 (1 ratings) — better
Positive reviews83.3% of reviews — better0.0% of reviews
Number of ratings24 — better1
Update frequencyEvery 4 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS13.0 — better18.1
Further details — not scored
Size149 MB21 MB
Age rating4+4+
DeveloperPapertrail Technologies LLCKyle Louderback

Customer experience

Papertrail Auto

All ratings24 ratings
Positive91.7%
Neutral4.2%
Negative4.2%
Written reviews12 reviews
Positive83.3%
Neutral8.3%
Negative8.3%

DiagonalOBDII

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

1 purchases

Papertrail Auto

Subscriptions1
  • Papertrail Pro7 Days trial$15.991 Month
4 purchases

DiagonalOBDII

Subscriptions4
  • Diagonal Premium Monthly$12.991 Month
  • Diagonal Premium Trial1 Month trial$12.991 Month
  • Shop Owner - Monthly$17.991 Month
Show 1 more
  • Diagonal Premium Yearly$99.991 Year

Questions

Is Papertrail Auto free?
Papertrail Auto is free to download, with in-app purchases available.
Is DiagonalOBDII free?
DiagonalOBDII is free to download, with in-app purchases available.
Which has better reviews, Papertrail Auto or DiagonalOBDII?
DiagonalOBDII is rated higher. Papertrail Auto averages 4.8 out of 5 from 24 ratings, while DiagonalOBDII averages 5.0 from 1 ratings.
Do Papertrail Auto or DiagonalOBDII have ads?
Neither Papertrail Auto nor DiagonalOBDII shows ads.
Which is updated more often, Papertrail Auto or DiagonalOBDII?
Papertrail Auto ships an update every 4 days, and DiagonalOBDII every 2 weeks. Most recently, Papertrail Auto was updated on October 9, 2026 and DiagonalOBDII on October 5, 2026.

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