File upload

File upload asks the visitor to attach one or more files. Use this block when the workflow needs an actual document, image, or asset — a CV, a brief, a screenshot, or any file the team needs to review later.

Applies to: Builder Widget Results

Best for

CV submissions, design briefs, screenshots, supporting documents, and any workflow that needs a real file the team can open and review.

Stores

A list of file references with name, type, and size in workflow answers. Files are stored in DialogMaker’s secure file storage and accessed via signed download links.

Routes

Continues along the step’s default path. File upload does not branch based on the answer.

At a glance

Capability	Supported
Single file or multiple files	Yes, configurable per block
Maximum files	Up to 5 when multiple files are allowed
Maximum size per file	Up to 25 MB (configurable per block)
File type restrictions	Yes, by MIME type or extension
Drag and drop	Yes
Per-file upload progress	Yes
Per-answer routing	No, all answers continue along the step’s default path
Contact field binding	Yes
WhatsApp and Messenger channels	Not supported

Example

A hiring workflow asks:

Please upload your CV.

The visitor drags a PDF onto the upload area, sees the file appear in the list with its size, and presses Continue. The file uploads to DialogMaker’s secure storage, and a reference to it is saved on the workflow answer. The recruiter opens the file later from the contact’s record.

When to use File upload

Use File upload when the workflow needs real files attached to the answer, not just text references to them.

Good use cases:

CV or resume submissions for a hiring workflow.
Design briefs, references, or example assets for a project intake.
Screenshots, logs, or recordings for a support workflow.
Supporting documents for an application or quote request.

Use a different block when:

The visitor only needs to share a link to a file: use URL input.
The workflow runs on WhatsApp or Messenger: those channels do not support file upload.
The answer is text or a short reference: use Text input or another typed input.

Add a File upload block

Open a workflow and go to the builder.
In the block sidebar, open Questions.
Add File Upload to a step.
Write the question text visitors should see.
Optionally restrict Accepted file types to specific MIME types or extensions.
Set Maximum size per file in MB (1-25).
Turn on Allow multiple files if the visitor should attach more than one file.
When multiple files are allowed, set Maximum files (2-5).
Choose where to save the answer.
Connect the next path.

Configure the question

The question text appears immediately before the visitor sees the upload area. Be specific about what file you want.

Good:

Please upload your CV (PDF or Word document).

Avoid:

Attach something for us.

State the expected document and the format. Visitors are more likely to upload a useful file when the prompt is concrete.

Configure the input

Accepted file types

Set Accepted file types to restrict what the visitor can upload. Use MIME types, extensions, or wildcards, separated by commas:

image/png, image/jpeg — only PNG and JPEG images.
application/pdf, .doc, .docx — PDF and Word documents.
image/* — all image types.

Leave Accepted file types blank to allow any file.

The widget enforces the restriction client-side and the server validates again before storing the file.

Maximum size per file

Set Maximum size per file in megabytes. The widget rejects files that exceed the limit before upload starts and shows a clear error to the visitor.

The platform-wide ceiling is 25 MB per file. Use a smaller limit when the expected files should be smaller — a 2 MB cap for screenshots, a 5 MB cap for CVs.

Allow multiple files

By default, the block accepts a single file. Turn on Allow multiple files to let the visitor attach more than one file in the same answer. The block then shows a Maximum files field where you set the cap (between 2 and 5 files).

Save the answer

File upload answers are always saved in workflow answers. The answer contains a list of file references — name, type, size, and an internal file ID — that the team uses to download the file from the contact’s record or via the API.

DialogMaker stores files in its own secure storage. The original files are never sent to third parties.

Common patterns

CV submission

Restrict to PDF and Word documents and cap the size at 5 MB. Single file is enough for most CVs.

Design brief intake

Allow multiple files (up to 5) so the visitor can attach a brief, references, and example assets in one step.

Support attachments

Allow images and PDFs, with a higher per-file cap (10-25 MB), so visitors can attach screenshots and exported logs.

Application supporting documents

Allow multiple files for documents the team needs to review together — proof of address, ID scan, references.

Answer output

When a visitor submits a File upload answer, DialogMaker stores a list of file references. The actual file content lives in DialogMaker’s secure storage; the answer contains the metadata and a file ID used to retrieve the file.

{
  "type": "file",
  "files": [
    {
      "fileId": "8d1e7e1c-1f10-4f44-9e2d-1c1d2c2d3e3f",
      "fileName": "jane-smith-cv.pdf",
      "contentType": "application/pdf",
      "sizeBytes": 184320
    }
  ]
}

Field	Meaning
`type`	Always `file` for this block.
`files`	The list of submitted files. Always at least one entry; up to Maximum files entries when multiple files are allowed.
`files[].fileId`	The internal identifier used to retrieve the file from DialogMaker’s storage.
`files[].fileName`	The visitor’s original file name, sanitized to remove path separators.
`files[].contentType`	The MIME type the browser detected.
`files[].sizeBytes`	The file size in bytes.

Routing behavior

File upload always continues along the step’s default path. The block does not branch on the answer.

The workflow always reaches this point only when the visitor submitted at least one file, so there is no implicit “no file attached” branch to handle separately.

Validation and limits

DialogMaker rejects invalid File upload answers when:

The answer is not a File answer.
No files are attached.
More than one file is attached when Allow multiple files is off.
More files are attached than Maximum files allows.
A file exceeds the configured Maximum size per file.
A file’s type is not in the Accepted file types list, when one is set.
The same file appears more than once.

DialogMaker also enforces upload rate limits — per visitor session, per workflow, and per visitor IP — to protect against abuse.

Troubleshooting

Problem	What to check
The visitor cannot select multiple files	Turn on Allow multiple files in the block editor and set Maximum files.
The widget rejects a file as too large	Check Maximum size per file. The platform ceiling is 25 MB; uploads larger than that are rejected even without a per-block cap.
The widget rejects a file as the wrong type	Check Accepted file types. Either widen the list (e.g. `image/*`), add the missing extension, or remove the restriction.
The visitor sees “Choose a file to continue” after pressing Continue	At least one file must be selected. If the visitor removed all files before pressing Continue, they need to reattach at least one.
The block does not appear in WhatsApp or Messenger workflows	File upload is web-only. Use a different block on those channels, or restrict the workflow to the web widget.
Upload progress stops mid-way	Network interruptions can stall uploads. The visitor should reselect the file and try again.