# Web interfaces for Roihu, Puhti and Mahti

## Intro

The web interfaces for Roihu, Puhti, and Mahti at
[www.roihu.csc.fi](https://www.roihu.csc.fi),
[www.puhti.csc.fi](https://www.puhti.csc.fi), and
[www.mahti.csc.fi](https://www.mahti.csc.fi) can be used to access the
supercomputers using only a web browser. A web interface for LUMI is also
available at [www.lumi.csc.fi](https://www.lumi.csc.fi), see the [LUMI
documentation](https://docs.lumi-supercomputer.eu/runjobs/webui/) for more
details.

Please note that logging in to Roihu, Puhti, and Mahti web interfaces requires
**multi-factor authentication**.
[More information on the Connecting page](connecting.md).

!!! warning "Scope"
    The HPC web interfaces are best suited for **interactive workloads** that
    consume a **modest amount of computational resources**. Some examples are
    **pre- and post-processing of data** in Jupyter Notebooks using
    **at most a few tens of CPU cores**, **small-scale AI/ML experiments**
    using a **single GPU**, and **data visualization** tasks. As such, the
    maximum length of interactive jobs is limited to 16 hours.

    Please note that the interactive applications in the web interfaces are
    **not** suitable for **multi-node** and **multi-GPU jobs**. Such workloads
    should ideally be carried out as standard
    [batch jobs](../running/getting-started.md). If you are new to batch jobs
    and command-line usage of the HPC environment, we recommend the
    [CSC Computing Environment](https://csc-training.github.io/csc-env-eff/)
    self-learning materials to learn how to get the most out of CSC's
    supercomputers.

## Available features

- **Features available in the Roihu and Mahti web interfaces:**
    - View, download, upload and move files between Allas, the supercomputer
      and your local computer
    - Open a shell on the login node
    - Open a persistent shell on a compute node
    - View running batch jobs
    - View disk quotas and project status
    - Launch interactive apps and connect to them directly from the browser:
        - Accelerated Visualization with applications such as Blender and ParaView (Roihu and Puhti only)
        - Desktop with applications such as Maestro and VMD
        - Julia-Jupyter
        - Jupyter
        - Jupyter for courses: An interactive Jupyter session specifically for
          courses
        - marimo (Roihu only)
        - MATLAB
        - MLflow
        - R-Jupyter (Roihu and Mahti only)
        - RStudio
        - TensorBoard
        - Visual Studio Code
- **Features available in the Puhti web interface:**
    - Puhti compute services have been decommissioned. Use the Puhti web interface only for login node
      connections, or for inspecting or moving data from the file system.

### Shell

The _Shell_ apps can be used to access the command-line of a supercomputer via
the web interface. You can either open a connection to the login nodes, or a
more persistent shell to the compute nodes. For more details, see the
[Shell](shell.md) page.

### File browser

The _Files_ app can be used to manage your files on the supercomputer and
access storage services such as Allas and IDA. For more information, check the
[Files and storage services](file-browser.md) page.

### Active jobs

Recent and running batch jobs can be viewed using the _Jobs_ section in the top
navbar and selecting _Active jobs_. Here you can view the current status of
your jobs and what kind of resources were requested. Deleting a running job
will cancel the job. 

In the future, it may become possible to submit batch jobs through the web
interface, but for now the recommended way to launch standard batch jobs is
using `sbatch` from the shell.

### Project view

Using the _Project view_ under the _Tools_ section in the top navbar, you can
view  current disk and project Billing Unit quotas on the supercomputers. For
more information, see the [Project view](project-view.md) page.

### File Deletion Explorer (beta)

The File Deletion Explorer is a tool in beta, that can be used on Puhti to
inspect the purge lists for scratch cleaning. See more details on the
[Managing data on Puhti and Mahti scratch disks page](../../support/tutorials/clean-up-data.md#using-lcleaner-and-the-web-interface-to-check-which-files-will-be-automatically-removed).


### Interactive apps

_Interactive apps_ are programs that can be launched and run on the compute
nodes and provide a graphical user interface. These are apps such as Jupyter
Notebook, RStudio and Visual Studio Code. For a full list of applications and
specific instructions, see the [Interactive apps](apps.md) page.

!!! info-label
    If an interactive app does not start, or does not work as expected, you can
    delete the session and try to launch the app again. See also
    [Troubleshooting](apps.md#troubleshooting).

### Partitions and resources

!!! warning-label
    Only a few partitions of the cluster are available for use in the web
    interfaces. Some apps also have a more limited set of partitions available
    than others.  
    The maximum length of jobs in the web interfaces is 16 hours to keep the
    queueing times for interactive resources short. If you have work that
    requires longer jobs than that, we recommend that you run your software as
    [batch jobs](../running/getting-started.md).

In the **Roihu web interface**, the `interactive`, `small`, `test`, and `gputest` partitions are
available. In the [Accelerated Visualization app](accelerated-visualization.md), the
`vizinteractive` partition is used, and will reserve one Nvidia L40 GPU. On the `gputest` partition,
one Nvidia GH200 GPU will be allocated. See the [Roihu partitions
page](../running/batch-job-partitions.md#roihu-partitions) for general information about queues on
Roihu.

In the **Mahti web interface**, the `interactive`, `small` and `gpusmall`
partitions are available. Selecting the `gpusmall` partition will allocate a
split Nvidia A100 GPU (a100_1g.5g) with 1/7th of the compute capacity of a full
A100. For more details about the split GPUs on Mahti, see the
[Mahti partitions page](../running/batch-job-partitions.md#mahti-partitions).

Puhti computing services have been retired as of 31 July 2026, so in the
**Puhti web interface**, you can only access login node resources and inspect the
storage in the system, until full retirement on 15 October 2026.