Free Gerber viewers compared: 6 options for 2026

Why a separate viewer at all

Your EDA tool shows the design. The fab builds the Gerber and drill files. Those are two different things, and the gap between them is where missing drill files, wrong outlines and mask problems hide. Opening the exported files in a second program, one that never saw the design, is the cheapest check there is.

There are plenty of free viewers. They differ in three ways that matter in practice:

• Where they run. A desktop install, a browser page that processes files on a server, or a browser page that processes them on your own machine.
• What they open. Single Gerber files, a full ZIP, RAR, Gerber X2 attributes, ODB++.
• What you get out. Some only display. Others measure, compare, run manufacturing checks or export to other formats.

Below are six free options, starting with our own. We built PCB Tools because none of the others covered the exact job we wanted, so we think it is the best fit for that job. We also say where another tool does something better. Every feature listed comes from the tool's own page or documentation, checked today.

The short version

1. PCB Tools: viewer, editor and converters in one page

PCB Tools is a free browser tool. You drop a ZIP or RAR archive (up to 15 MB) with RS-274X Gerber and Excellon drill files from KiCad, Altium Designer, EasyEDA, Eagle, Fusion 360 or similar, and the layers are identified from their file names. No account and no install.

What sets it apart is what happens after the viewing step, without leaving the page:

• Gerber editor. Add traces, copper fills, text and drill holes, erase areas or delete objects, then download the modified Gerbers as a new ZIP. Edits are made on a temporary copy, so the original archive is untouched. It is meant for small corrections to finished files, not for designing a board.
• Gerber to 3D. Export OBJ with MTL materials, 3MF, PLY, one STL per layer or a single combined STL, with your own board, copper, mask and silkscreen thicknesses. Useful for enclosure design and fit checks.
• Gerber to PDF. A vector PDF at true 1:1 scale, with a combined top view, a combined bottom view and one page per layer, plus a scale legend to check the print with a ruler.

On privacy: the site has no ads, no cookies and no third party analytics. The archive is processed on our server in a temporary session that is deleted automatically.

Where it falls short. It does not run manufacturing rule checks, so it shows you the board but will not flag a 0.08 mm gap for you. Files are uploaded to a server, which a fully local viewer avoids. And the 15 MB limit can be tight for large boards with many layers.

Best for: checking a Gerber set before ordering and then doing something with it (a quick fix, a 3D model, a printout) in the same place.

2. KiCad GerbView: the most complete free desktop viewer

GerbView ships with KiCad. The documentation describes it as a Gerber (RS-274X) and Excellon drill file viewer, and it reads Gerber X2 attributes, so you can highlight items by component, net or attribute. Up to 32 files can be displayed at once.

The toolset is strong: a measure tool, sketch mode, a diff mode for comparing layers, mirroring, a D code list and a "Show Source" command that opens the raw Gerber text. You can export to the KiCad PCB editor, but the manual is clear that this is limited: negative objects cannot be converted and flashed items become vias.

Where it falls short. You need a full KiCad install, and it is a viewer: no 3D export and no one click PDF of all layers.

Best for: KiCad users and anyone who wants X2 attribute inspection and layer comparison offline.

3. Gerbv: the long running open source option

Gerbv describes itself as a viewer for Gerber RS-274X files, Excellon drill files and CSV pick and place files. It overlays several files and measures on the displayed image. The current project site at gerbv.github.io offers builds for Linux (.deb and .rpm), Windows and macOS, and says official releases are published on GitHub. The older SourceForge page lists GPLv2 and still shows version 2.7.0 from 2021, so download from the GitHub site.

Where it falls short. The interface is dated, and installing a desktop app is more friction than a quick check needs.

Best for: Linux users, scripting through its libgerbv library, and checking pick and place files against copper.

4. Ucamco Reference Gerber Viewer: the format owner's renderer

Ucamco owns the Gerber format specification and runs a browser viewer at gerber-viewer.ucamco.com. RS DesignSpark describes it as a way to check fabrication files before manufacturing: drag files in or use "Open files", change the view, toggle units and measure between items.

Where it falls short. It is a viewer only. No editing and no export.

Best for: a second opinion when two viewers disagree on how a file renders. A "reference" render from the format owner settles most arguments.

5. HQDFM by NextPCB: when you want manufacturing checks

HQDFM is the one to pick if you want rule checks. The online viewer needs no sign up, accepts ZIP or RAR with RS-274X, X2, Excellon or a .kicad_pcb file, offers 3D visualization and lists over 50 DFM checks. The desktop suite (Windows only) lists more than 1,200 DFM and DFA checks, ODB++ viewing, an impedance calculator and panelization tools. NextPCB says uploaded files are deleted after 24 hours.

Where it falls short. It is a manufacturer's tool, so the checks follow that fab's capabilities, not necessarily yours. The full suite is Windows only.

Best for: a DFM pass before ordering, especially if NextPCB is a fab you are considering.

6. Flux online viewer: fully local in the browser

Flux offers a free viewer built on the open source tracespace toolchain. Its page says files are parsed and plotted in your browser, with no upload to a server. It opens a ZIP, a full package or a single file, also from a direct URL, and lets you isolate layers or switch between top and bottom views.

Where it falls short. It is viewing only: no editing, no 3D export, no PDF.

Best for: confidential boards where you do not want the files to leave your machine. This is a real advantage over PCB Tools, which processes files on a server.

Which one to use

For most pre order checks, our suggested routine is short. Drop the ZIP into the PCB Tools Gerber viewer, go through the guide to checking Gerber files before ordering, and if something looks odd, open the same file in the Ucamco viewer or GerbView to confirm. If the layer names confuse a viewer, the Gerber file extensions guide explains what each one should contain.

Sources

All sources checked on 26 October 2026.

• KiCad, GerbView reference manual
• Gerbv, Gerbv project site and downloads
• SourceForge, gerbv project page
• RS DesignSpark, Online Reference Gerber Viewer
• NextPCB, HQDFM free online Gerber viewer and DFM tool
• Flux, Online Gerber Viewer
• PCB Tools, Privacy policy

Information in this article comes from the public documentation of manufacturers, standards bodies and software vendors as of the publication date and may have changed. Check current conditions with the company concerned before you order. Company and product names are trademarks of their owners; mentions are editorial, with no sponsorship or affiliate relationship. See the terms of use.

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