How to open a LAS file
- 1
Open the .las
Drop the file or tap the box to choose one. No file at hand? Try the sample scan of a small plot with a house, trees and a pond. Large tiles are thinned evenly so they stay smooth.
- 2
Pick a colour mode
Use the file's RGB if the scan has colour, or colour by elevation, intensity, classification or return number. The elevation scale shows the height range under the view.
- 3
Look around
Drag to orbit, scroll or pinch to zoom. Top gives a plan view like a map; South and East give side views for checking heights, slopes and power lines.
- 4
Filter and measure
Untick classes to hide them, or press Only to see just ground or buildings. Turn on Measure and tap two points to get the distance, the horizontal distance and the height difference.
- 5
Save what you need
Download the shown points as PLY (real coordinates or centred) or XYZ text, or take a PNG screenshot of the view.
Private by design. The LAS file is read by JavaScript in your browser and drawn on your device. It is never uploaded, so client surveys and unpublished site scans stay private.
What is inside a LAS file
LASASPRS LiDAR exchange format- The standard binary file for airborne, drone and terrestrial laser scans, defined by the American Society for Photogrammetry and Remote Sensing. Versions 1.0 to 1.4 are in use; 1.2 and 1.4 are the most common.
HeaderBounds, scale, offset- A fixed block with the point count, the min and max X, Y and Z, and a scale and offset. Points are stored as whole numbers and turned into real coordinates with them, which is how LAS keeps millimetre precision on large map coordinates.
VLRsCoordinate system- Variable length records after the header hold the coordinate system, as GeoTIFF keys or as WKT text. The viewer shows the EPSG code and the unit (metres or feet) so you know what the numbers mean.
Point formats0 to 10- Every point has X, Y, Z, intensity, return number and class. Formats 1, 3 and 4 to 10 add GPS time; 2, 3, 5, 7, 8 and 10 add red, green and blue; 6 to 10 are the LAS 1.4 layouts with up to 256 classes.
LAZCompressed LAS- LAZ is the same data packed with LASzip, often 7 to 20 times smaller. This page reads uncompressed .las; it recognises a .laz and tells you how to unpack it with the free laszip tool, PDAL or CloudCompare.
Choosing a colour mode
RGB shows the scan as a photo-like cloud, but only when the file holds colour, which is common for drone photogrammetry and coloured LiDAR and rare for older airborne tiles. Elevation colours points from blue (low) to red (high) and is the quickest way to read terrain, roofs and tree heights; the range ignores the highest and lowest two per cent so a few birds or pits do not flatten the scale.
Intensity is the strength of the laser return. Road markings, roofs and wet ground stand out, which helps when there is no RGB. Classification uses the ASPRS codes the data provider assigned: 2 ground, 3 to 5 vegetation by height, 6 building, 7 noise, 9 water and so on. Return number shows where the laser passed through something: first returns on canopies, later returns under trees.
Coordinates, units and measuring
Most LiDAR tiles use a projected system such as UTM or a state plane, with X as easting and Y as northing. The viewer reads the EPSG code and unit from the file and shows sizes and measurements in that unit, so a tile in US survey feet reads in feet. If the file has no coordinate system, the numbers are shown as plain units.
Measurements snap to the nearest point you tap, so they are as good as the point spacing: on a tile with 8 points per square metre, expect a few centimetres to a decimetre. The horizontal distance and the height difference are shown on their own, which is what you need for a building height, a tree height or the drop along a slope. A file in latitude and longitude gives distances in degrees, and the viewer warns you.
Big files and the PLY download
LiDAR tiles often hold tens of millions of points. The viewer loads up to 2 million on a computer and 1 million on a phone by default, spread evenly across the file, and you can raise or lower that with the Load setting. The header facts always describe the whole file, and the panel says how many points are shown.
The PLY keeps each shown point with its colour, intensity and class. The default PLY writes the real coordinates in double precision for GIS and survey tools. The centred PLY moves the cloud to the origin and writes floats, which Blender, MeshLab and our PLY tools handle better; the shift is written in the header so you can move it back.
What this LAS viewer does
Reads LAS 1.0 to 1.4
All point formats 0 to 10, with RGB, intensity, classes and return numbers.
Five colour modes
RGB, elevation with a scale bar, intensity, ASPRS classification and return number.
Class filter
Point counts per class, with show, hide and Only to isolate ground, buildings or vegetation.
Measure
Distance, horizontal distance and height difference between two tapped points, in the file unit.
File facts
LAS version, point format, total points, EPSG code, units, size, software and date.
Private by design
Runs in your browser. Files are never uploaded and no account is needed.
Limits, honestly
- LAZ (compressed) files are recognised but not opened; unpack them to .las first.
- Very large tiles are thinned for display; the PLY and XYZ hold the shown points, not every point in the file.
- Files over 1 GB are not opened, and phones may run out of memory well before that.
- COPC, E57 and PTS scans are not read here; export them as LAS from CloudCompare or your scanner software.
- There is no meshing or ground-model (DEM) creation; this is a viewer.