Comparison

First vs OTR Diagnostics

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

Head to head
About

First

Connect your mobile device to a commercial vehicle's diagnostic port to monitor its health status. Understand fault codes, view vehicle specifications, and track trip data to improve uptime and aid in service and repair.

Highlights
  • Connect to vehicle diagnostic port
  • Monitor vehicle health status
  • View active and inactive fault codes
  • Display vehicle specifications (VIN, ECU info)
  • Track trip data (fuel, miles, speed, hours)
  • Generate and share vehicle reports
Features
Read full description

NEXIQ First-Link™ is an application that provides important features to the drivers and service technicians of commercial vehicles and equipment. These features help the driver connect the mobile device to the diagnostic port; they also monitor the vehicle's health status and increase the vehicle's uptime. If a Check Engine Light is illuminated, the application assists the driver to understand the cause so that he can seek assistance (i.e., service and repair), if needed. Service technicians can utilize the information gathered by the application to aid in vehicle service and repair. Features include: • Faults – Active and Inactive fault codes present at the time of connection are displayed. • Vehicle Specs – Vehicle information including VIN, ECU software and hardware information is displayed. • Life / Trip – Displays trip-specific information related to fuel usage, miles, maximum speed, cruise control speed, hours of operation, etc. • Parameters – Displays parameters specific to the modules on the vehicle (e.g., engine, transmission, etc.) • Report – Generates a session-specific report containing vehicle information (i.e., faults, vehicle specs, parameters, and life/trip information); can be uploaded to the cloud, emailed, etc. • Sharing - Enables the driver to share vehicle information gathered to dispatch, service providers, etc. • OnCommand® Support - Optional feature to allow users to upload health reports to the OnCommand® servers. • Blue-Link Mini firmware update to v1.09, if the adapter has older firmware.

About

OTR Diagnostics

This app helps heavy-duty truck owners diagnose and resolve common issues like fault codes, regen problems, and derates. It provides plain-language explanations of error codes, allows for bi-directional commands to fix issues, and monitors live truck data to prevent downtime.

Highlights
  • AI-powered fault code explanation
  • Bi-directional commands for repairs
  • Reset active/inactive fault codes
  • Run forced DPF/SCR regens
  • Live data monitoring
  • Fault code history tracking
Features
Read full description

OTR Diagnostics — Trusted by 10,000+ Truck Owners Dealing with regen problems, nonstop alerts, fault codes, and unexpected derates on your heavy duty truck? You are not alone. More than 10,000 truck owners and fleets trust OTR Diagnostics to take control, cut downtime, and avoid expensive dealer visits. Powered by OTR Assist + OTR LINK 2 This is more than a scan tool. OTR Assist is your AI partner, breaking down fault codes in plain language and helping you troubleshoot and decide if you can keep driving or need service now. Paired with OTR LINK 2, our proprietary Bluetooth adapter, you get faster connection speeds, more accurate fault code data, and more live data parameters than ever before. It is 5X better than previous hardware. Ask us how to get a FREE upgrade today. Commands That Keep You Moving With bi-directional commands built right into OTR Diagnostics, you are no longer stuck waiting on a shop to do what you can handle yourself. Reset active and inactive fault codes Reset the entire aftertreatment system Reset derates that slow you down Reset soot levels after a DPF service Run forced DPF or SCR regens right from the cab These commands put you back in control, saving you time, money, and downtime. Fault Code Insights Go beyond a flashing dash light. OTR Diagnostics helps you understand fault codes with the same level of detail as dealer software, but in plain language you can actually use. Decode your dash lights Uncover the root causes of issues Track how often a problem occurs Know which repairs or parts are needed Live Data Monitoring Want to know if your regen is working? Want to monitor exhaust temps, soot levels, or DEF? OTR Diagnostics lets you see your truck’s vitals in real time so you can spot issues before they stop you. Common live data parameters include: DPF fluid level DPF soot level EGR valve position Aftertreatment exhaust temps Boost pressure Accelerator pedal position Engine fuel delivery pressure Available live data may vary depending on the engine model your device is connected to. Explore Your History Recurring problems? OTR Diagnostics logs every fault code and command so you can see when issues happened, when they were cleared, and how long regens lasted. Proven. Tested. Backed by Support We run OTR Diagnostics, OTR Assist, and OTR LINK 2 on our own fleet of test trucks including late model Paccar MX engines to make sure everything works before it reaches you. That is why more than 10,000 drivers already trust OTR Diagnostics. Made in Michigan. Built for You We engineer, assemble, and ship right from our shop in Macomb, MI. If you are nearby, stop in and see us. Coverage We support a wide range of heavy duty engines: Cummins: CM871, CM2150, CM2250, CM2350 (2008–2024) Detroit Diesel: DD60, MBE, DD13, DD15, DD16 (2008–2024) Paccar: MX11, MX13 (2011–2024), PX7, PX9 (2008–2024) Volvo: D11, D13, D13TC, D16 (2014–2024) Mack: MP7, MP8, MP8HE, MP10 (2014–2024) For the full list of compatible models, call or text us at 586-799-4375. Need Help or Have Questions? Call or text us anytime at 586-799-4375 or email support@otrperformance.com.

Screenshots

First2 screens
OTR Diagnostics4 screens

Verdict

The call

The clearest difference is rating: OTR Diagnostics at 4.0 against First's 2.3. OTR Diagnostics also leads on review sentiment (55% vs 17%) and update cadence (fortnightly vs every 5 months). First's advantage is monetization model (free vs free with in-app purchases) and iOS requirement (11.0 vs 17.6). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

OTR Diagnostics holds the better App Store score, 4.0 against 2.3. That said, the two scores are not equally well evidenced: OTR Diagnostics has 99 ratings behind it against 16, so its average is the more settled of the two. Written reviews point the same way: 17% of First's written reviews are positive against 55% of OTR Diagnostics's.

UpkeepUpdate frequency

First ships an update every 5 months, OTR Diagnostics fortnightly. The most recent releases landed on October 5, 2026 and October 6, 2026 respectively.

Scorecard6 real differences · 4 level
First versus OTR Diagnostics: the parameters behind the verdict, then further details
ParameterFirstOTR Diagnostics
PriceFreeFree
Rating2.3 (16 ratings)4.0 (99 ratings) — better
Positive reviews16.7% of reviews55.2% of reviews — better
Number of ratings1699 — better
Update frequencyEvery 5 monthsFortnightly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS11.0 — better17.6
Further details — not scored
Size128 MB267 MB
Age rating4+4+
DeveloperSnap-on Inc.OTR Performance

Customer experience

First

All ratings16 ratings
Positive25.0%
Neutral12.5%
Negative62.5%
Written reviews12 reviews
Positive16.7%
Neutral16.7%
Negative66.7%

OTR Diagnostics

All ratings99 ratings
Positive70.7%
Neutral7.1%
Negative22.2%
Written reviews58 reviews
Positive55.2%
Neutral10.3%
Negative34.5%

Bugs and requests

First

Not enough reviews yet to summarise bugs or requests.

OTR Diagnostics

Reported bugs

10 issues
  • App constantly disconnects from device
  • Generic code option disappeared
  • Forced regen is no longer consistent
  • AI assistant not working
  • App asks to do things not available in app
Show 5 more
  • Bluetooth connection rejects
  • App doesn't work without data connection
  • Forced regen not activating after updates
  • Login authentication errors
  • Cannot start regen process on newer models

Requested features

5 requests
  • Remember email address for login
  • Allow offline functionality without data connection
  • Add option to change speed
  • More detailed diagnostic information
  • Allow basic subscription to work on multiple VINs

In-app purchases

None

First

No in-app purchases

None

OTR Diagnostics

No in-app purchases

Questions

Is First free?
First is free to download, with no in-app purchases.
Is OTR Diagnostics free?
OTR Diagnostics is free to download, with no in-app purchases.
Which has better reviews, First or OTR Diagnostics?
OTR Diagnostics is rated higher. First averages 2.3 out of 5 from 16 ratings, while OTR Diagnostics averages 4.0 from 99 ratings.
Do First or OTR Diagnostics have ads?
Neither First nor OTR Diagnostics shows ads.
Which is updated more often, First or OTR Diagnostics?
First ships an update every 5 months, and OTR Diagnostics fortnightly. Most recently, First was updated on October 5, 2026 and OTR Diagnostics on October 6, 2026.

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