---
title: "Web Access Technical Reference"
slug: "technical-reference"
description: "Explore the technical limitations of Web Access, including file size limits, directory item counts, and supported file types for optimal performance."
updated: 2026-06-18T14:12:07Z
published: 2026-06-18T14:12:07Z
canonical: "docs.nasuni.com/technical-reference"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nasuni.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Web Access Technical Reference

The goal of this document is to outline the technical considerations for supported features in Web Access.

This document has been updated for version 10.1.

---

## **Items in a Directory**

To provide optimal performance, Nasuni recommends keeping directories under 10,000 items. Depending on the workload, folder listings of 10,000 items should take no more than 20-30 seconds.

Web Access does support folders with up to 128,000 items. For folders containing more than 128,000 items, data might still be returned, up to a maximum of 256,000 items. Any items beyond this limit would not be included in the response.

## **File and Folder Name Length**

File and folder names can be up to **255 bytes** long.

***Note:*** *This limit is in* ***bytes****, not characters. Some characters (like those in UTF-8) might use more than one byte, so the actual number of characters might be less.*

## **Path Length**

The maximum length of a path, composed of multiple segments of up to 255 bytes each, is 4000 bytes. The path does not include the share's name.

## **Valid or Invalid Characters in Names of Folders, Files, and Paths**

Web Access does not allow for the creation of files and folders with special characters in the name such as: `?`, `<`, `>`, `\`, `:`, `*`, `|`, `"`.

If a file or folder name (created outside of Web Access) contains one of these characters, Web Access renders it as a tofu character ``.

Unicode characters, including emojis, are supported for files and folders.

## **Upload File Size Limits**

File uploads are **limited to 35 GiB** (Gibibytes).

## **Download File Size Limits**

There are no default file size limits for downloading a single file without using Zip compression. The download must complete before the user’s session expires, which is set to 12 hours by default. Also, you can download folders as a ZIP file without any limitation on the number of files or subfolders included.

### 

## **Preview Limitations**

### **Preview File Size Limit**

There is a maximum pre-viewable file size **limit of 250** **MB** (Megabytes).

### **Preview Conversion Timeout Wait**

For non-PDF document files, there is a **25 second timeout** when waiting for the file conversions to PDF, which is required when previewing such files.

### **Supported Previewable File Types**

The following file types are supported:

#### **Images**

Images with the following extensions are supported: `jpg`, `jpeg`, `gif`, `bmp`, `png`, `svg`, `tiff` *, and* `tif` *.*

#### **Video**

Videos with the following extensions are supported: `mp4`, `m4v`, `mov`, `webm`.

> ***Note****: If the browser does not support the codec used to encode the video, the video cannot be played natively.*

#### **Audio**

Audio files with the following extensions are supported: `mp3`, `wav`, `ogg`.

#### **Document (via Microsoft 365 web previewer)**

- Microsoft PowerPoint
  - pptx, pptm, ppsm, ppsx, potx, potm, ppt, pps, pot
- Microsoft Excel
  - xlsx, xlsm, xlsb, xls
- Microsoft Word
  - docx, dotx, docm, dotm, dot, doc
- Microsoft Visio
  - vsdx, vsdm, vsd, vdw
- OpenDocument
  - Presentation: odp
  - Spreadsheet: ods
  - Text: odt
- Other formats
  - csv (Comma-Separated Values)
  - rtf (Rich Text Format)

#### **PDF Documents**

PDF documents (`pdf` extension) are previewed inline within the browser.

#### **Other Document Previews**

These document formats are converted to PDF files for previewing:

- `txt`
- `odg`
- `ott`
- `otp`
- `ots`
- `otg`

If the conversion takes longer than 25 seconds to appear, a message appears offering you the option of downloading the file.

If Microsoft 365 is not enabled, the following document formats are also converted to PDF files for previewing:

- `rtf`
- `doc`
- `docx`
- `dot`
- `dotx`
- `ppt`
- `pptx`
- `pot`
- `potx`
- `xls`
- `xlsx`
- `xlt`
- `xltx`
- `csv`
- `ods`
- `odp`

If the conversion takes longer than 25 seconds to appear, a message appears offering you the option of downloading the file.

Documents must be under 250 MB to be previewed.

## **Shared Item Limits**

There are two license levels for Web Access

- Basic - Available to all customers.
- Advanced - Requires a license.

### **Number of Shared Items**

With a Basic license, each user can create at most one shared link per folder or file.

With an Advanced license, each user can create up to 250 shared links per folder or file.

### **Number of Recipients of Email-Shared Links**

A default **limit of 100 email recipients** is imposed for shared links sent via email.

### **Number of Shared Items Displayed on the Your Shared Items Screen**

Up to **10000 shared items** are displayed on the Your Shared Items screen (for each user).

### **OTP Generation Lock Time**

A cool-off **limit of 30 seconds** is in place for how frequently a One Time Password can be requested by a shared link recipient.

## Background Tasks

Release 10.4 introduced background tasks with the ability to delete folder hierarchies (recursive delete).

### Execution Limits

Each user has the ability to run two background tasks at the same time. Users can initiate deletes beyond this limit. Tasks are held until slots for that user become available.

An appliance has the ability to run **n** background tasks at the same time, where **n** is the number of virtual CPUs. Users can initiate deletes beyond this limit. Tasks are held until capacity becomes available.

### Task Retention

Completed tasks are purged after 30 days.