# GDS Viewer

Free online GDS viewer. Open and preview chip layout files (.gds, .oas, .oasis) directly in your browser — no upload, no software.

> Canonical page: https://elysiatools.com/en/viewers/gds

- **Category:** Diagrams

- **Supported formats:** .gds, .oas, .oasis

## Overview

This GDS viewer renders chip layout files directly in your browser. GDS (.gds, GDSII) is the industry-standard format for integrated circuit layout data, used by every major semiconductor foundry and EDA tool. OAS (.oas, .oasis) is the modern compressed successor. Pick a sample layout or choose your own .gds / .oas file to preview it instantly, with no upload.

## When to use

- You received a .gds or .oas file from a chip design flow and want to view it.
- You need a quick, private preview of an IC layout.
- You want to inspect chip geometry on any device.

## How it works

- Select a built-in sample layout or choose your own .gds / .oas / .oasis file.
- The viewer parses the layout format and renders the geometry in your browser — nothing is uploaded.
- Pan and zoom to inspect the chip layout layers.

## Use cases

- Previewing IC layout designs.
- Checking GDS/OAS exports from EDA tools.
- Inspecting chip mask data before tape-out.

## Samples

- **Sample GDS**: A GDS sample for in-browser preview

## Frequently asked questions

### What is a GDS file?

GDS (.gds, GDSII — Graphic Data System II) is the industry-standard binary format for integrated circuit layout data, originally developed by Calma in the 1970s. It stores polygon geometry organized by layer, along with cell hierarchies, text labels and layout structure.

### What is OASIS?

OASIS (.oas, .oasis, Open Artwork System Interchange Standard) is the modern successor to GDSII, standardized by SEMI in 2004. It uses efficient compression (run-length encoding, repetitions) to achieve much smaller file sizes than GDSII while preserving the same geometric data.

### Are my GDS files uploaded?

No. Layout files you open from your device stay on your device and are parsed locally. Only the public sample file is requested from the server.

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