Everything you need to load, analyze, and tune from your Maptuner datalogs — step by step.
The Log Viewer requires a one-time Datalog License. This license is tied to your browser — you only need to enter it once per device.
You can purchase a Datalog License directly from the link below to unlock the Log Viewer and Editor Helper.
Buy a Datalog License →Go to log-viewer.html. You'll see a license entry screen on first visit.
Paste the key you received after purchase and click Activate. The key is saved to your browser — you won't need to enter it again on this device.
Simply enter the same license key again. One license works across your devices.
Both Maptuner X and Maptuner Nano record datalogs as .mtx files. There are two ways to load one:
Drag your .mtx log file directly onto the Log Viewer window. It will load instantly.
Click the Open log button in the top toolbar and select your file from your computer or phone.
Once a log is loaded, you land on the Graphs view. This is where you visually analyze your run.
Move your cursor over the chart to see exact values for all visible channels at that point in time.
Click and drag on the chart to zoom into a specific time range. Double-click to zoom back out.
The bar at the bottom shows the full run. Drag it to pan through the log without losing context.
Each channel has its own color. Click the color swatch in the sidebar to change it.
Channels are the individual data streams in your log (RPM, speed, throttle, coolant temp, etc.). You control which ones are visible.
Click the colored dot next to any channel name in the left sidebar to toggle it on or off.
Channels you use most can be pinned to the top of the list so they're always easy to find.
Click the AFR target button to overlay a reference line on your wideband channel. Useful for quickly spotting lean or rich areas.
Click Clear frames to unload the current log and load a new one without refreshing the page.
The Editor Helper tab takes your log data and turns it into actionable fuel table corrections — a starting point for your next tune revision.
Click the Editor Helper button in the top toolbar (next to Graphs).
The Editor walks you through: selecting your log data → reviewing the fuel map → applying corrections. Each step has its own tab at the top.
Cells are color-coded: green = run richer, red = run leaner. Cells with little or no data are dimmed — don't rely on them.
Use the export button to download your corrected table, ready to import into Maptuner.
Make sure the file is a .mtx file exported directly from Maptuner X. Other formats are not supported.
Double-check for extra spaces when pasting. If the problem persists, open a support ticket and include your license key.
The license is saved per browser. Just enter your key again — it will activate instantly.
Chrome or Edge on desktop give the best experience. Safari and Firefox work but may render charts slightly differently.
Before using the Editor Helper to generate fuel corrections, make sure the RPM and load axis values in the app match the axis of the fuel table in the tune you're working with. If the axes don't line up, the corrections will be applied to the wrong cells and the results won't be usable.