A .drl file is a firmware format called EXCELLON. Excellon Drill File

How do I open a .drl file without installing software?

Upload your .drl file to OpenAnyFile. Our browser-based tool instantly detects and displays it — no downloads needed.

What program creates .drl files?

.drl files are typically created by Excellon.

Can I convert .drl to another format?

Yes. OpenAnyFile converts .drl to PDF.

Is it safe to open .drl files online?

Yes. OpenAnyFile processes files in a secure, isolated environment. Files are automatically deleted and all transfers use HTTPS.

Can I open .drl on my phone?

Yes. OpenAnyFile works on all mobile browsers including iPhone and Android.

Open EXCELLON Files Online Free

Here's what matters: To [open EXCELLON files](https://openanyfile.app/excellon-file), specialized software is typically required due to their highly technical nature. These files delineate the precise drilling information for Printed Circuit Boards (PCBs).

Technical Structure

EXCELLON filenames often use extensions like .DRL, .DRLGRB, or simply follow a numerical sequence (e.g., 1.DRL). An EXCELLON file is essentially a text-based instruction set, detailing the x,y coordinates and tool assignments for every hole to be drilled on a PCB. It operates much like a simplified G-code for drilling, specifying tool changes (T01, T02), drill hits (XxxxxYyyyy), and sometimes routing paths. The format originated with Excellon Automation and became a de-facto standard for PCB manufacturing. While primarily character-based, slight variations exist, especially in units (inches/mm) and coordinate precision, which are typically defined in a header or accompanying aperture file. These files are critical alongside Gerber files for PCB fabrication.

How to Open EXCELLON Files

Directly opening EXCELLON files for viewing or editing typically requires dedicated CAD/CAM software used in PCB design and manufacturing.

PCB Design Software: Programs like Altium Designer, Eagle, KiCad, or OrCAD include viewers for EXCELLON and other manufacturing files.
Gerber Viewers: Many generic Gerber viewers also support EXCELLON files, as they are part of the standard PCB fabrication data set. Examples include GC-Prevue, GerbView, and online Gerber viewers.
Text Editors: Since EXCELLON files are plain text, you can open them with any text editor (Notepad, VS Code, Sublime Text) to inspect raw data. However, this offers no graphical representation.
Online Tools: For quick viewing, several online services allow you to upload and visualize your EXCELLON data alongside Gerber files. Our platform can assist in helping you [how to open EXCELLON](https://openanyfile.app/how-to-open-excellon-file) and similar technical formats.

Compatibility

EXCELLON files are universally compatible with virtually all PCB manufacturing equipment and related software within the electronics industry. They are a core component of the data package sent to a board house for fabrication, alongside Gerber layers. However, issues can arise from inconsistent unit definitions (e.g., inches vs. millimeters) or coordinate precision settings between the design software and the manufacturing equipment. Always ensure the EXCELLON file's unit and format specifications match the expectations of the fabrication house.

Common Problems and Troubleshooting

The most frequent issues with EXCELLON files include:

Incorrect Units: Drill holes appear in the wrong locations or at incorrect sizes if the file specifies inches but the machine expects millimeters (or vice-versa).
Missing Tool Definitions: The file might call for a tool (e.g., T03) that is not defined in the header or in an accompanying tool file.
Coordinate Precision Mismatch: Differences in the number of decimal places specified for X,Y coordinates can lead to drill holes slightly off-target.
Software Interpretation: Different Gerber viewers or CAM tools might interpret minor formatting variations differently.
Corrupted File: Like any data file, corruption during transfer can render the EXCELLON file unreadable.

To troubleshoot, always verify the units (IN/MM), format (absolute/incremental), and tool definitions within the file or its accompanying documentation. Many errors can be caught by reviewing the file in a dedicated Gerber viewer before manufacturing.

Alternatives and Related Formats

While EXCELLON is dominant for drilling, there are related and alternative formats:

Gerber Files: These are the primary layers (copper, solder mask, silkscreen) of a PCB, distinct from drill data. Together, EXCELLON and Gerber files form the standard PCB manufacturing data set.
IPC-2581 (GenCAM): An emerging, more integrated format designed to encompass all PCB manufacturing data (layers, drills, netlist, bill of materials) in a single XML-based file. It aims to replace the disparate Gerber and EXCELLON files.
ODB++: Another integrated data format for PCB manufacturing, widely adopted in the industry, which also consolidates design and manufacturing information.
G-code: While EXCELLON is specific to PCB drilling, [GCODE format](https://openanyfile.app/format/gcode) is a broader numerical control programming language used for automating machine tools, including drilling, milling, and 3D printing. EXCELLON can be seen as a specialized variant of this concept.
Proprietary Formats: Some older or specialized CAM systems might use their own proprietary drill data formats, though EXCELLON remains the industry standard for exchange.

For general [Firmware files](https://openanyfile.app/firmware-file-types) or embedded programming, formats like [ARDUINO format](https://openanyfile.app/format/arduino) or [JLINK format](https://openanyfile.app/format/jlink) are more relevant, but distinct from PCB manufacturing data.

Converting EXCELLON Files

Converting EXCELLON files often involves transforming them into a visual representation or integrating them into a unified PCB fabrication data stream.

EXCELLON to PDF: While not a true "conversion" in the data sense, many Gerber viewers allow you to export a visual representation of the drill layer to [EXCELLON to PDF](https://openanyfile.app/convert/excellon-to-pdf) for documentation or review. This provides a printable image of the drill pattern.
To Integrated Formats: EXCELLON data can be re-exported or integrated into newer formats like IPC-2581 or ODB++ using CAM engineering software.
To DXF/DWG: Some specialized tools can convert drill hit locations to CAD drawing formats like DXF or DWG, useful for mechanical integration, although this loses tool specifics.
Online Converters: A limited number of online [file conversion tools](https://openanyfile.app/conversions) or services can facilitate basic transformations or visualizations of EXCELLON data. Refer to our [all supported formats](https://openanyfile.app/formats) page for more options.