Best practices

Guidelines for optimal performance

While the Encord platform is able to handle large volumes of data, we strongly recommend working within the following limits to ensure smooth operations and limit loading times.



The limits outlined below apply for both the SDK, and the web-app.


Maximum number of data units5,0002,5001000
Maximum image/video/DICOM file size1 GB1 GB25 MB
Maximum JSON file size100 MB100 MB10 MB
Label row / Annotation task limit50 MB50 MB10 MB
Model predictions import limit50 MB50 MB10 MB
Maximum resolution4K (3840 x 2160 px)4K (3840 x 2160 px)4K (3840 x 2160 px)
Number of frames per video200,000 (2hrs at 30fps)200,000 (2hrs at 30fps)200,000 (2hrs at 30fps)

When a project is too large, the files in the attached dataset(s) need to be resized, as shown below.



Learn how to resize your videos here.


Maximum number of projectsUnlimitedUnlimited10
Maximum dataset size per project100 GB100 GB100 GB
Maximum number of labels per project1,000,0001,000,0001,000,000
Maximum number of instances per project20,0005,0005,000
Maximum number of instances per workflow project100,0005,0005,000
Maximum number of tasks per project5,0002,5001,000

Encord Active

Maximum number of images500,00050,00050,000


Maximum number of usersUnlimitedUnlimited1



Even if you stay within these limits, we recommend to create a new project every 6 months and archive the existing project

Access control

Encord currently supports the following roles:

  • Annotator: Responsible for completing annotation tasks
  • Reviewer: Responsible for completing review tasks
  • Annotator + Reviewer: Able to complete both annotator and reviewer tasks
  • Team manager: Able to complete both annotator and reviewer tasks and access team management features
  • Admin: Full access to all project features. In order to successfully attach ontologies and datasets to a given project, a user must have Admin permissions against each target resource.

For collaborative teams using our SDK, we recommend creating shared service accounts and creating SSH keys for those shared accounts. For example, to have several people create ontologies, datasets, and projects programmatically, create an email account for use with Encord (for example, [email protected]) and generate an SSH for that email account.

Screen size

Encord isn't supported on small screens such as tablets. The minimum application window resolution needs to be 800x600px.

Supported data



Please see our Supported data page for detailed information for all supported data and file types, as well as addressing any data related issues such as long buffering times

Video formats

We support a range of formats and codecs. For optimized performance we recommend using the following video formats:

  • .mp4 file with h.264
  • .mp4 with vp9

Please ensure that videos have a constant frame rate and no audio tracks. The label editor will inform you when we detect audio present in the video files. You can remove audio tracks in videos already in the Encord platform by using the media re-encoding feature in our platform, detailed here.

Other formats and codecs may be supported, but we cannot guarantee compatibility, for more information please see our blog or relevant section in our documentation.

Image formats

The platform supports a range of image formats. For most cases we recommend to use:

  • .png
  • .jpeg

For more information please see the relevant section in our documentation.

Resolution of data / media

The resolution of any videos and images should be limited to 4k pixels (3840 x 2160 px) to avoid issues. If you have other requirements, please contact us first and we will help evaluate suitability for specific use-cases.

Keyboard shortcuts

Be sure to check out all the keyboard shortcuts available when using the label editor, to help speed up your annotations!

Recommended browser

We strongly encourage the use of Chromium-based browsers (e.g. Google Chrome, Brave, Edge) when using Encord in most cases. Please see the table below for more details.

ModalityRecommended browserNotes
VideosChromeIncludes image sequences
ImagesChromeIncludes image groups. Excludes TIFF files.
DICOMFirefoxNo tab memory limit allows large files to load. However, large files can slow down your computer significantly.
Images (TIFF)SafariDue to Chromium-based browser limitations, TIFF files can only be viewed in the Label Editor using the Safari browser. More details can be found here.

This is primarily due to optimizing performance & ensuring data integrity. Modern browsers give no control over deterministically rendering media files (e.g., displaying frames and rendering videos). Further, we also recommend turning off hardware acceleration in Chrome.

Hardware acceleration adds another layer of uncertainty to video rendering in the browser. To eliminate unexpected behavior, we strongly recommend disabling hardware acceleration.



If you have any questions on the above or are experiencing performance issues please contact us at [email protected]