Public comment requested: Cloud Optimized GeoTIFF (COG) Standard

Please note:  This Request is scheduled to close on 17 Septebmer 2022
Open Date: 
Thursday, 2022-08-18
Closing Date: 
Saturday, 2022-09-17

The Open Geospatial Consortium (OGC) is seeking public comment on the Cloud Optimized GeoTIFF (COG) Candidate Standard, which aims to formalize, as an OGC Standard, existing practices already implemented by the community, such as the GDAL library or the COG explorer and other implementations

COG allows for efficient streaming and partial downloading of imagery and grid coverage data on the web and enables fast data visualization and geospatial processing workflows. COG-aware applications can efficiently stream/download only the parts of the information they need to visualize or process web-based data. With so much remote sensing imagery available in cloud storage facilities, the benefits of optimizing their visualization and processing will be widespread. COG is one of the preferred formats used in STAC catalogs, and sits alongside other emerging cloud-optimized formats of relevance to OGC, such as Zarr, COPC, and GeoParquet.

The candidate COG Standard specifies how TIFF files can be organized in a way that favors the extraction of convenient parts of the data at the needed resolution while remaining compatible with tradicional TIFF readers. It also specifies how to use HTTP (or HTTPS) to communicate only the part of information needed without downloading the complete file.

This candidate Standard depends on the TIFF specification and the OGC GeoTIFF Standard. For large files, it depends on the BigTIFF specification. The standard takes advantage of some existing characteristics of the TIFF specification and the existing HTTP Range Request specification (IETF RFC 7233) and does not modify them in any way.


Comments can be submitted to a dedicated email reflector for a thirty day period ending on the "Close request date" listed above, or by submitting an issue to the OGC COG GitHub public repository. Comments received will be consolidated and reviewed by OGC members for incorporation into the document.

Please submit email comments using the following link: requests [at] (Click here to submit comments). The link provided above should include a standard template in the message body. If the preloaded message body does not work properly using your mail client, please refer to the following template for the message body: Comments Template


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Subscribing to the the list will also allow you to view comments already received, which can be found in the List Archives.

Or follow along on the the OGC COG GitHub public repository.