What is the E57 file format?
Files with the .e57 extension store 3D point cloud and imaging data captured by 3D scanners and LiDAR - light detection and ranging - devices. The format is an open standard defined by ASTM International as ASTM E2807, structured around a combination of binary data sections and an embedded XML metadata tree. Point fields are bit-packed to the declared precision, reducing file size without a general-purpose compressor; every physical page additionally carries a CRC-32 checksum for built-in integrity verification. Every .e57 file opens with the 8-byte ASCII file signature ASTM-E57 at offset 0, making format identification unambiguous.
Contents of .e57 files
.e57 files can store such objects as:
- point clouds (3D coordinate sets - the core payload),
- color and intensity information as point attributes,
- 2D images (panoramic or pinhole photos linked to a scan),
- metadata including sensor pose, coordinate systems and file-related information.
A single .e57 file can hold multiple registered scans, each with its own position and orientation, which flat formats such as .LAS cannot.
Usage of .e57 files
The .e57 format is supported by terrestrial laser scanners and 3D cameras from leading manufacturers, as well as airborne and mobile LiDAR systems. Captured data can then be edited and processed using professional software tools. .e57 files can store scans of:
- building and architectural elements,
- geologic surfaces,
- atmospheric and environmental objects.
ASTM E57 files are used in many research fields, engineering, the construction industry, and geodesy. Being vendor-neutral, the format was designed for storing and exchanging 3D point cloud data between different hardware platforms. Related interchange formats include .LAZ, .PLY and .PCD.
Security & safety
RISK: LOWAn E57 file is measurement data with no executable code, so opening it in point-cloud software is safe. The practical cautions are non-malware: files can be multi-gigabyte and overwhelm low-RAM machines (subsample, tile or convert to LAZ), and scan data of private property, infrastructure or interiors can be sensitive - mind cloud uploads and sharing. Download tools (CloudCompare especially) from their official sites to avoid lookalike 'free 3D/point-cloud viewer' pages bundling adware.
Format details
in a nutshellFULL NAMEASTM E57 3D Imaging Data Exchange fileaka E57 point cloud, ASTM E2807 file
DEVELOPERASTM International - E57 Committee on 3D Imaging Systemssince 2011 (ASTM E2807 standard published; format finalised 2009-2011)
CATEGORY3D Image Files
MIME TYPEapplication/octet-stream
TYPEOpen point-cloud / 3D imaging interchange format - XML metadata + binary point data
STANDARDOpen · royalty-free
MAGIC BYTES · FILE SIGNATURE
OFFSET
0001020304050607
HEX
4153544D2D453537
ASCII
ASTM-E57
An .e57 file begins with a binary file header whose first field is the 8-byte ASCII signature "ASTM-E57", followed by major/minor version and pointers to the XML section. The human-readable XML metadata block lives near the end of the file; the bulk is binary point data in compressed/packed "binary sections".
Programs that open E57 files
Windows5 apps
CloudCompare
Open-source File > Open the .e57 to view, measure, crop, subsample and convert the cloud. Best free E57 viewer.
Autodesk ReCap
Paid Import the .e57 to register/clean and produce an .rcp/.rcs for Revit, Navisworks and AutoCAD.
Leica Cyclone / CloudWorx
Paid Open .e57 for registration and modelling in the Leica reality-capture workflow. 
macOS1 app
Linux2 apps
PDAL (with E57 support)
Open-source Command line: read/convert E57 (when built with the E57 plugin), e.g. 'pdal translate in.e57 out.las'. Technical details
deep spec| File signature | 8-byte ASCII string `ASTM-E57` at offset 0 - mandatory header identifier present in every valid file |
| File structure | Binary file header → one or more binary data sections holding points → embedded XML descriptor near the end of the file |
| Byte order | Little-endian throughout all binary sections |
| MIME type | `application/x-e57`; also commonly served as `application/octet-stream` |
| Point compression | Bit-packing of each point field to its declared bit precision; no general-purpose codec (unlike LAZ) |
| Integrity checking | CRC-32 checksum covering every physical page across the entire file - catches corruption in both binary and XML sections |
| Per-point color | Optional RGB color up to 8 bits per channel plus a scalar intensity value, stored as per-point attributes |
| Multi-scan support | A single file can contain multiple Data3D scan objects and Image2D panoramas with no fixed count limit |
| Coordinate systems | Stores both scanner-local and globally registered coordinate frames per scan using rigid-body (rotation + translation) transforms |
| Point count capacity | Bounded only by 64-bit addressing, supporting billions of points in a single file |
| Typical file size | Tens of MB to several GB; a multi-scan terrestrial survey commonly exceeds 1 GB |
| Embedded 2D images | Spherical panoramas and pinhole-camera images can be embedded and linked to their parent scan object |
| XML metadata | Human-readable XML tree embedded in the file describes scan parameters, sensor pose, data layout and spatial reference systems |
| Platform support | Windows, macOS and Linux via the `libE57` / `E57Format` open-source C++ reference library |
| Released | 2011 (ASTM E2807 standard published; format finalised 2009-2011) |
| Latest version | ASTM E2807-11 (current standard); libE57 / E57Format are the de-facto reference implementations |
| Open standard | Yes · royalty-free |
| Specification | www.libe57.org |
E57 conversions
Possible
.E57 .LASGUIDE
Yes - open the E57 in CloudCompare and save it as LAS in a few clicks.
How to convert
.E57 .LAZGUIDE
Yes - open the E57 in CloudCompare (free) and save it as LAZ in under a minute.
How to convert
.E57 .PLYGUIDE
Yes, E57 can be converted to PLY - CloudCompare (free) is the fastest way.
How to convert
.E57 .PTSGUIDE
Yes, E57 converts to PTS - the fastest free route is CloudCompare's File > Save As on any platform.
How to convert
.E57 .RCPGUIDE
Yes - import the .e57 into Autodesk ReCap and index it; the resulting .rcp/.rcs files work directly in Revit,…
How to convert
Not possible
Community Q&A
asked by users
R
Frequently asked questions
How do I open an E57 file for free?
Use CloudCompare - a free, open-source point-cloud viewer for Windows, macOS and Linux. File > Open the .e57 to view, measure, crop and subsample the cloud, then export to LAS/LAZ/PLY if needed.
What's the difference between E57 and LAS?
Both store 3D points, but E57 is richer: one E57 can hold MANY registered scans, sensor positions and panoramic photos with multiple coordinate systems, while LAS is a single flat point list (popular in GIS/airborne LiDAR). E57 dominates terrestrial scanning; LAS dominates aerial/GIS.
How do I convert E57 to LAS or LAZ?
Open the .e57 in CloudCompare and 'Save As' LAS/LAZ, or use PDAL ('pdal translate in.e57 out.laz'). LAZ is the compressed version. Per-scan metadata and embedded images don't carry over to LAS.
Why is my E57 file so large?
It stores millions of uncompressed-ish 3D points (plus colour and sometimes panoramic images). Subsample or crop it in CloudCompare, or convert to LAZ for a big size reduction.
How do I get an E57 scan into Revit or AutoCAD?
Import the .e57 into Autodesk ReCap, register/clean it and index it to .rcp/.rcs, then attach that point cloud in Revit, Navisworks or AutoCAD and model over it.
Can I turn an E57 point cloud into a 3D CAD model (DWG/solid)?
Not by file conversion. A point cloud has to be modelled/reverse-engineered into surfaces or solids (in ReCap + Revit/AutoCAD, or Geomagic). You attach the cloud as a reference and build CAD from it.
References
1libE57 - software tools and the ASTM E2807 standardwww.libe57.org
2ASTM International - E2807 Standard Specification for 3D Imaging Data Exchangewww.astm.org
