File preview

Haiilo generates a preview for certain file formats so that they can be viewed directly in Haiilo without downloading them.

We summarize the most important information and questions in this article.

Supported file formats

The preview function of Haiilo supports the following file formats:

  • Images
    • .jpg
    • .gif
    • .png
    • .tiff
    • .x-png
    • .x-icon
  • Texts
    • .docx
    • .odt
    • .pdf
    • .pptx
    • .txt
  • Videos
    • .mp4

If you use a different format, you will need to download the file beforehand to view it locally on your device.


Office files

The preview for text documents is currently implemented for Office files from version 2007 (.docx and .pptx). The preview function shows only the first page of the file.

All Office files in the old format (.doc and .ppt) have no preview.

Apple files

The files from Apple products (Keynote, Numbers and Pages) do not have previews.

Video files

Videos are played in Haiilo using the browser's "video" tag. This means that the browser (or ultimately the operating system) is responsible for decoding the video and audio with the codecs installed. Haiilo has no influence on the installed codecs on the end devices.

Videos uploaded to Haiilo are played in their original format and are not converted. We recommend to produce the videos in such a way that the used codecs are covered by the largest possible number of end devices. Due to the large variety of combinations of end devices, browsers and installed codecs, we cannot provide a suitable list. Level 5.1 or lower should be used for the encoding profile for the web, so that a display via end devices (such as cell phones) can also take place.


Can you choose or create the preview image for documents yourself?

The preview image for documents is generated by the document itself. The first page of the file is automatically shown as a preview.

What are the ideal resolutions for images in Haiilo?

We have not defined any pixel defaults. It is enough if you choose the correct aspect ratio for your images.

What is the maximum file size for images and files?

The maximum file size for uploading images is limited to 10 MB and for files to 1GB.

What does "alternative text" mean for images?

In various places you can add an alternative text to images. This text serves as an image description, which is then displayed when you move the mouse over the image.

What can we do if an image is distorted or cropped incorrectly?

Haiilo does not compress images, but uses the original resolution. 

However, images are scaled in some widgets and also for thumbnails. This means that rectangular images may be squeezed to a square format and the image appears distorted.

A very simple workaround in this case is to crop the image in advance. As a teaser image you select the section you want to have, crop the whole thing in a program of your choice to the appropriate aspect ratio, so that the image is displayed correctly.

Why are our images displayed landscape, although it is in portrait format?

There are images where the corresponding meta data has a different format. Should this be the case, it happens that an image is displayed upside down. This has no connection with Haiilo.

The reason is mostly the so-called orientation flag in the data. Modern digital cameras, as well as cell phones and tablets, automatically detect the posture with which the image was taken (e.g. whether the camera was turned on edge) and store this together with the actual image in its so-called EXIF metadata. 

Modern image software reads this data and then always displays the image "correctly" oriented, even if the camera was rotated when the image was taken. While "outdated" image software ignores this data and always shows the image from the pure camera perspective.Now there are two possible causes for this problem:

  • Either the PC software considers/ignores the stored orientation or    
  • The server software (external service provider or rich text editor) ignores/ignores this EXIF data. 

You can solve the problem in this way: Use a good image editing program (e.g. Adobe Photoshop) to save the image without all META data "optimized for web" and correctly aligned. Then upload it again.

What can we do if an image has been uploaded but certain users cannot view the image?

In Haiilo there are several ways to store files: We have on the one hand the document app, which can be included on pages or in communities and is visible to everyone (*as long as they have the right in their user role), and on the other hand images can be uploaded directly to articles or e.g. to image galleries. These images are automatically uploaded to the "Files" folder in the respective page/community, which is neither visible nor editable for the ordinary user. Only the admin has access here to edit the files. However, this has nothing to do with the visibility of the images. So if an image is no longer visible on the page, have the admin check if the image is still there or if it was accidentally deleted.

Another possibility why colleagues cannot see uploaded images can be that the images were uploaded by the user to his private file folder. This can be found under the respective user profile under "My files".

Why is the order of images attached to a timeline post messed up?

You can upload multiple images in one post on the Timeline. One of the images will be displayed dominantly, each additional image will be displayed scaled smaller as a preview.

If you upload less than 9 images, the number of images per line will be adjusted here. If you upload more than 9 images, a plus symbol will appear in the last image to show that there is more to see here.


There is no way to influence the order of uploaded images, they are randomly uploaded to Haiilo.

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