The following FPS limits are allowed: 60 (default and recommended) and 144 FPS. Additionally, the game must run smoothly with the same FPS as the limit; otherwise, the result will be invalid. Only valid results are accepted by the NFS.onl database, and kickStart in version 2.7 or greater is required.

In-game, only up to three unique upgrades from TJ can be used, and only those combinations that are genuinely possible to obtain in the career mode. Any gameplay-related hacks enabling something that is impossible in the original game (such as modifying the number of racers) will lead to disqualification.

Trainers or any other cheating tools and mods affecting gameplay or physics are not allowed, regardless of whether kickStart detects it. Car geometry must be original, or from the latest "smol model fix" for 206 and Lancer by AJ_Lethal.

Multiple accounts are not allowed.

Competition results are considered part of the commons, accessible to all for sharing and discussion.

Drifting techniques are allowed, such as DT (Double Tapping, for digital input like keyboards or d-pads) and DS (Double Steering, using analog controls). However, the game itself applies steer smoothing to joypads unless they're recognized as a wheel. In order to make DS possible, you can simply enable "Identify as a steering wheel" in the settings of the Lap Recorder plugin (part of the NFS.onl Software). You'll find that option in kickStart under "Track records", then "Advanced options". Alternatively, you can edit the Windows registry - as described in the guide linked below.

Download the NFS.onl Software and extract the .zip file into your NFS Underground game folder. It's recommended to use a portable installation under something like C:\Games due to writing permissions. If not, you may need to run it with administrator rights, although this is not recommended. However, if your game runs as admin, kickStart (the launcher) needs to run as admin, too.

Next, run kickStart.exe and then start the game. In the game, navigate to "Quick Race" and then select "Free Run" or "Sprint". Choose your car and track, and begin your cruise.

If you need a high-performance ride, check out the "Saved game files" tab under the settings in kickStart, where you can create a new profile, import a 100% savegame and swap unique upgrade parts.

Once you've completed your first lap, you'll find your data in kickStart under "Hot Laps". There, you'll also find a button to upload your data to the online database. Click it, and if it's your first upload, you'll be prompted to register your nickname. Once that's done, you can enable "Automated synchronization" on the "Track records" tab in the settings.

That's it! Every lap record will now appear in the online database almost instantly. Happy hotlapping!

Please note that kickStart must be running in the background for recording (in the settings, on tab "Main configuration": "Keep open during game" and/or "Close to tray" must be enabled under "Options"), and this feature only works with the 1.4 game version.

In case you experience invalid results (red font in overlay and an asterisk behind lap times) or if the recorder isn't working, click on the button "Open settings" and (at the bottom) navigate to the tab "Track records" where you should find a button to set the basics to the defaults. Click on it and start the game again. If it's still not working, double-check if cars are original and have allowed TJ combinations, then restart kickStart.

For more detailed information, press the F1 key while in kickStart.

Additional mods are not supported, but if it's only visual, like improving texture quality, it's alright. Extra Options is also allowed, but keep in mind that any mod can cause unexpected behavior; therefore, it's always recommended to play as original as possible.

Especially after updates, false positive detections and file deletions by antivirus programs may occur (mostly temporary), which can lead to functional problems and error messages. To avoid this, you can specify the entire game folder as an exclusion. Instructions on how to do this are described in the following link.

This site, including the help section, is still under construction. If you require additional assistance and information, we recommend joining the Retro Racing Point Discord server. There, under #nfs-underground, you'll find a dedicated thread for kickStart where you can get the help you need. Don't forget to check the pinned messages!

If you haven't done so, open the settings in kickStart and navigate to "Track records" (tabs at the bottom). Then push the "Update profile" button and log in. On your profile, click "Edit," and then under "#nfs_onl" you will see two symbols: one for YouTube and one for Twitch. Enter your channel(s) there, then submit the changes.

Next, ensure your YouTube Uploads or Twitch Highlights contain at least the following information in the title or description: track name, in-game time, and car model. If NOS in Free Run was used, mention that as well. The hashtag #nfs_onl can be used to trigger a post in the video channel/thread on Discord, but this is optional.

Done. Now, you just need a little patience while everything is correctly assigned. This can take a while.

https://cadence.moe/video-games/need-for-speed-underground
An online map browser for Olympic City by Cadence

https://ug1.pp.ua/trackmap
Track-Map, an online map browser made with Flash by radicalSpeed

https://nfsu.fun/ or https://nfs-online.ru/
Monitoring and stats from online multiplayer game servers by webair

https://nfs.fandom.com/wiki/Need_for_Speed:_Underground
Need for Speed Wiki on Fandom

https://www.pcgamingwiki.com/wiki/Need_for_Speed:_Underground
NFSU section on PCGamingWiki

http://nfsa.ca/f5881 or https://nfsmods.xyz/mod/2720
The smol model fix by AJ_Lethal

https://ug1.pp.ua/guide
Prima's Official Strategy Guide by Dan Irish (Prima Games, 2003)

https://youtu.be/usj29yiTIF0
Craft tutorial for DIY analog stick precision rings

https://tinyurl.com/nfsu-keyboard-records
Google Sheets: World Records on Keyboard (and other devices)

https://balathruin.github.io/nfsd/ug1
Need for SpeedDocs by Balathruin

https://retroachievements.org/game/3114
Retro Achievements for the PS2 version

https://virtuallenge.com/games/racing/nfsu1
Comprehensive telemetry tools by Aleksandr Tropakov
Link points to the last snapshot on archive.org as the website seems down.
The software can be downloaded from here.

https://www.speedrun.com/nfsu
NFS Underground on Speedrun.com
Note (by Redhair): This site has actively sought to discredit my software through misleading claims and technical half-truths. A moderator circulated warnings across multiple communities, citing baseless evidence including:

- The presence of winspool.drv (a standard DLL used in all modern Delphi applications - despite the misleading name, it's not a driver),
- String references dubiously presented as "proof" of code theft - despite the referenced mods not using Delphi and some even having no public source available.
They additionally labeled my software suspicious due to UPX packing - a widely used tool employed by both malware and legitimate applications.

The campaign escalated when this moderator contacted a modding site owner (a personal friend), who allegedly demanded my full source code under threat of removal. However, no one from the site, its owner, or any involved party ever contacted me directly. Even if they had, I would not have complied anyway.
Subsequently, public statements falsely asserted the site had officially requested the source code. This fabricated narrative was then used to frame the software's removal as "proof" of untrustworthiness. In reality, the removal occurred without any communication or evidence, driven purely by external pressure and biased assumptions.

Critically, no concrete evidence of malicious behavior has ever been presented - only speculation designed to sow distrust.
For the sake of transparency, I will not withhold the link. Everyone should judge for themselves.