14 analyzers
AFR drift, Butterworth filters, VE and correlation. Run one, chart it in a click.
14 analyzers. 18 log formats. Free, forever.
Lambda delay tables
Mine your logs for injector-to-wideband delay, binned by RPM and load.
Heatmap histograms
Average any channel over RPM × MAP. Copy straight into your tune.
Five tools, one log
Every view reads the same log, one keystroke apart.
Log Viewer
Stack up to 10 plot panels on one synchronized timeline, or overlay a second log to compare two pulls. Min/max legend, playback from 0.25x to 8x, and the GPS track map beside the chart.
Scatter Plot
Plot any two channels against each other to see how they move together, colored by a third.
Histogram
Average any channel over RPM × MAP, or count hits per cell. Copy the grid straight into your tune.
Lambda Delay
Finds injector pulse-width steps and measures how long the wideband takes to answer. Every cell shows its sample count and confidence.
Accel Enrichment
Detects tip-ins, shifts the lambda window by the measured delay, and suggests a starting correction per RPM and throttle-rate cell.
New in 3.0
All releasesThe Night Drive look
An indigo-black interface with one cyan accent, a sunset redline and mono numbers. One slider takes it from quiet Stealth greys to full Ultra glow, and never touches your data colours.
Compare two logs
Overlay a second log on the same chart, before and after a tune change. Channels pair by name on a shared scale, and Align at cursor lines the two pulls up.
A new export sheet
Charts, scatter plots, histograms and tuning tables export on one clean sheet, PDF or PNG, on light Paper or dark Graphite. PDFs carry real, selectable text.
Lambda delay and accel enrichment tables
Measures how long the wideband takes to respond, binned by RPM and load, and the lean or rich excursion on every tip-in with a suggested correction. Runs across several logs at once.
TunerStudio MSL, RaceChrono and Torque Pro
Open .msl datalogs from TunerStudio and RealDash, RaceChrono CSV v3 sessions, and Torque Pro trackLogs, with the track map ready out of the box.
GPS track map
Logs with GPS draw the track beside your chart: lap detection, any channel painted onto the racing line, and opt-in satellite backgrounds.
Color blind mode and High contrast
Okabe-Ito series and cividis heatmaps with direct labels, or true black grounds and white text. Both meet WCAG AAA.
MCP server for AI
Claude Desktop can drive UltraLog: load files, select channels, compute formulas and query data with 23 tools.
Supported ECUs and loggers
CSV and binary logs, opened as the ECU writes them.
- HaltechNSP CSV exports from Elite, Nexus and IC-7 ECUs..csv
- ECUMaster EMU ProCSV exports from EMU Pro and EMU Black..csv
- RomRaiderRomRaider Logger CSVs for Subaru ECUs, and generic Time-first CSVs..csv
- SpeeduinoNative MLG binary logs. No export step..mlg
- rusEFINative MLG binary logs, including 1000+ field firmware..mlg
- AiMXRK and DRK binary files from AiM loggers and dashes..xrk.drk
- Link ECUPCLink LLG binary logs..llg
- Emerald K6/M3DEM Soft logs: .lg2 channel list plus .lg1 records..lg1.lg2
- MegaSquirtTunerStudio CSV exports from MS1, MS2, MS3 and MS3-Pro..csv
- TunerStudio MSLLegacy ASCII datalogs from TunerStudio and RealDash..msl
- MHD TuningCSV logs from BMW N54, N55, S55 and B58 flashed with MHD..csv
- Motorsport ElectronicsME Tuner CSV exports from ME221 and ME442..csv
- RaceChronoCSV v3 session exports: GPS, phone sensors and OBD/CAN on one timeline..csv
- Torque ProtrackLog CSVs from the Android OBD-II app..csv
- Woolich Racing TunedWRT CSV exports from motorcycle ECUs..csv
- BlueDriver OBD-IILive data CSVs from the BlueDriver scan tool..csv
- DynamicEFIEBL WhatsUp CSVs from modified GM TBI systems..csv
- LocomotiveDatalogger CSVs with a TimeStamp and Customer header..csv
Latest release
On GitHub- Windows: the zip now holds
ultralog.exe(it wasultralog-windows.exe). - Waits for the app to close. The updater waits for UltraLog itself to exit before it replaces the file, and it keeps the name you run the app under.
- Odd folder names work. Install folders with accented letters (like
C:\Users\José) or a%in the path no longer break the update. - Linux replaces the binary in one step and always restarts the app, so a failed update leaves your old version in place and running.
- macOS is unchanged: the update opens the new DMG for you to drag into Applications.
- Linux, 3.1.0 or older: download
ultralog-linux.tar.gzbelow and install 3.1.1 by hand once. Updates after that install from the app.