Browser-local analysis · Nothing uploaded

CSV Datalog Viewer

Q: Which CSV datalog formats are supported?

The viewer supports comma, semicolon, tab, and pipe-delimited text, quoted fields, metadata rows before the header, decimal commas, numeric time or sample columns, and ISO date-time columns. It is designed for exported CSV logs, not proprietary binary log files.

Q: Can I compare two ECU or automotive logs?

Yes. Add up to three logs. The viewer aligns them from their first time or sample and overlays channels whose normalized names match, such as RPM, boost, AFR, throttle, or vehicle speed.

Graph automotive, ECU, OBD, race, and sensor logs in seconds. Time and channels are detected automatically, so you can compare pulls, zoom into anomalies, and export evidence without an account.

No signup Up to 3 logs 100 MB each

Drop CSV datalogs here

CSV, TSV, semicolon, or pipe-delimited text · up to three 100 MB files

Your log stays in this tab No file upload, retention, account, or public link.

Logs1

Source rows0

Duration—

Numeric channels0

Detected format—

Drag across the chart to zoom. Use the wheel to zoom around the cursor.

Visible window

Values, statistics & thresholds

Thresholds flag recorded values; they are not safety recommendations.

Channel	Cursor	Min	Max	Average	Your min / max	Outside

Ready for a CSV datalog.

Local by architectureRaw logs never leave your browser.

Made for time seriesGraphs and cursor values, not only rows.

Dialect awareComma, semicolon, tab, pipe, and preambles.

Compatibility without a format dropdown

Built for exported logs, not one vendor

Open CSV data from common automotive and tuning workflows or from a custom sensor logger. The parser looks at the file structure, not its filename, and reports what it detected.

ECU

Automotive & tuning

Best-effort support for CSV exports resembling COBB Accessport, VCDS/VAG-COM, Haltech, MoTeC, MegaSquirt/TunerStudio, EcuTek, MHD, bootmod3, JB4, RomRaider, and similar tools.

OBD

OBD & road logs

Review RPM, vehicle speed, throttle, boost or manifold pressure, fuel trims, intake temperature, and other numeric PID channels against relative time.

DAQ

Sensor & test data

Generic equipment logs work when they contain a delimited header and at least two numeric data rows. ISO timestamps and sample numbers are accepted as x-axes.

Product names identify common export vocabulary only. CSV Datalog Viewer is independent and is not certified, sponsored, or endorsed by those vendors.

Three steps to a useful view

From raw CSV to the moment that matters

The viewer makes an informed first view, then leaves the exact channels, range, smoothing, and thresholds under your control.

Open locally

Drop one log or up to three comparison logs. A Web Worker detects the delimiter, metadata preamble, header, time axis, numeric channels, and units.

Start with a smart preset

Overview prioritizes familiar channels such as RPM, throttle, boost, AFR or lambda, knock, timing, pressure, temperature, and speed when present.

Zoom, test, and export

Drag or wheel to zoom, hover for synchronized values, enter your own min/max thresholds, then download a chart PNG or the visible sampled rows.

Purpose-built analysis

Why this is different from a CSV table viewer

A spreadsheet shows cells. A datalog viewer preserves time, synchronizes channels, and helps you narrow a long recording to an explainable window.

Capability Generic CSV table CSV Datalog Viewer

Time-series graphSometimes one chartSynchronized channel rows

Automotive presetsNoOverview + five focused groups

Compare pullsManual joinsUp to three aligned logs

Threshold reviewFormulasPer-channel min/max highlights

Raw file handlingVariesNever uploaded

Large-log behavior you can see

Responsive without pretending every point fits on screen

A display only a few hundred pixels wide cannot meaningfully show millions of points. Extremely long logs are sampled in the background for responsive drawing. The detected source row count, parsed row count, and sampling stride are reported in the viewer.

Statistics and exports operate on the parsed sample when sampling is active. Keep the original file as the source of truth for forensic or compliance work.

CSV datalog viewer FAQ

Before you open a log

Direct answers about formats, privacy, comparison, limits, and safe interpretation.

What is a CSV datalog viewer?

A CSV datalog viewer turns rows from an ECU, OBD, race-data, tuning, or sensor export into time-aligned graphs. This viewer detects numeric channels and lets you zoom, compare values, set thresholds, and export the result.

Are my CSV logs uploaded?

No. File reading, parsing, graphing, comparison, and export happen in the current browser tab. Raw bytes, filenames, headers, values, and charts are not sent to this site or its analytics.

Which CSV datalog formats are supported?

Comma, semicolon, tab, and pipe-delimited text are supported, including quoted fields, metadata rows before the header, decimal commas, numeric time or sample columns, and ISO date-time columns. Proprietary binary log files must be exported first.

Can I compare two ECU or automotive logs?

Yes. Add up to three logs. They are aligned from their first time or sample and overlaid when normalized channel names match, such as RPM, boost, AFR, throttle, or vehicle speed.

How are large CSV logs handled?

Files up to 100 MB can be opened. Parsing runs in a Web Worker, and extremely long logs are sampled for responsive drawing. The viewer reports the sampling stride instead of hiding it.

Can this tool tell me whether a tune is safe?

No. The viewer helps inspect recorded values but does not diagnose an engine, choose safe thresholds, or replace the logger manufacturer's guidance or a qualified tuner.