File Uploads

Accept file uploads with your form submissions. Files are stored securely and accessible via signed URLs.

Requirements

File uploads are available on all plans with varying limits.

Plan	Max File Size	Max Files/Submission	Storage
Starter	10 MB	2	100 MB
Pro	25 MB	10	10 GB
Business	50 MB	25	50 GB
Enterprise	100 MB	50	Custom

Supported File Types

Starter Plan

Images: JPEG, PNG, WebP, GIF

Documents: PDF

Pro Plan

Images: JPEG, PNG, WebP, GIF, AVIF

Documents: PDF, Word (.doc, .docx)

Business & Enterprise

All file types are supported.

Video Addon (Pro+)

With the Video Addon ($29.99/mo):

Video files up to 2 GB

MP4, WebM, QuickTime formats

50 GB video storage

Resumable uploads

HTML Form Upload

html

<form action="https://atlasforms.app/f/abc123xyz" method="POST" enctype="multipart/form-data">
  <input type="text" name="name" required>
  <input type="email" name="email" required>
  <input type="file" name="attachment">
  <button type="submit">Send</button>
</form>

Important: Use enctype="multipart/form-data" for file uploads.

JavaScript Upload

javascript

const form = document.querySelector('form');

form.addEventListener('submit', async (e) => {
  e.preventDefault();

  const formData = new FormData(form);

  const response = await fetch('https://atlasforms.app/f/abc123xyz', {
    method: 'POST',
    body: formData // Don't set Content-Type - browser handles it
  });

  const data = await response.json();
  console.log('Files uploaded:', data.files);
});

Multiple Files

html

<input type="file" name="documents" multiple>

Or multiple file inputs:

html

<input type="file" name="photo">
<input type="file" name="resume">
<input type="file" name="cover_letter">

Response with Files

json

{
  "success": true,
  "submission_id": "550e8400-e29b-41d4-a716-446655440000",
  "files": [
    {
      "id": "file-uuid-1",
      "filename": "photo.jpg",
      "type": "image/jpeg",
      "size": 245000
    },
    {
      "id": "file-uuid-2",
      "filename": "resume.pdf",
      "type": "application/pdf",
      "size": 102400
    }
  ]
}

Accessing Uploaded Files

Via Dashboard

Click any submission to view uploaded files. Click a file to download or preview.

Via API

bash

# Get file info
curl "https://atlasforms.app/api/v1/files/{file_id}" \
  -H "Authorization: Bearer fep_your_api_key"

# Download file
curl "https://atlasforms.app/api/v1/files/{file_id}/download" \
  -H "Authorization: Bearer fep_your_api_key" \
  -o filename.pdf

Response

json

{
  "id": "file-uuid",
  "submission_id": "submission-uuid",
  "original_filename": "document.pdf",
  "mime_type": "application/pdf",
  "file_size_bytes": 102400,
  "file_category": "document",
  "uploaded_at": "2024-01-15T10:30:00Z",
  "download_url": "https://..."
}

Video Uploads

For large video files (up to 2 GB), use the Video Addon with resumable uploads.

Enable Video Addon

Go to Dashboard → Settings

In the Subscription section, click Add to Plan under Video Addon

Complete checkout

Resumable Upload API

javascript

// 1. Initialize upload
const initResponse = await fetch('https://atlasforms.app/api/v1/uploads', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer fep_your_api_key',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    filename: 'video.mp4',
    fileSize: 1073741824, // 1 GB
    mimeType: 'video/mp4',
    formId: 'abc123xyz'
  })
});

const { uploadId, uploadUrl, chunkSize } = await initResponse.json();

// 2. Upload chunks
const file = document.querySelector('input[type="file"]').files[0];
const chunks = Math.ceil(file.size / chunkSize);

for (let i = 0; i < chunks; i++) {
  const start = i * chunkSize;
  const end = Math.min(start + chunkSize, file.size);
  const chunk = file.slice(start, end);

  await fetch(`${uploadUrl}?part=${i + 1}`, {
    method: 'PUT',
    body: chunk
  });
}

// 3. Complete upload
await fetch(`https://atlasforms.app/api/v1/uploads/${uploadId}/complete`, {
  method: 'POST',
  headers: { 'Authorization': 'Bearer fep_your_api_key' }
});

Resume Interrupted Upload

javascript

// Get upload status
const status = await fetch(`https://atlasforms.app/api/v1/uploads/${uploadId}`, {
  headers: { 'Authorization': 'Bearer fep_your_api_key' }
}).then(r => r.json());

// Resume from last completed chunk
const startChunk = status.completedChunks;

File Validation

Atlas validates files server-side:

File size - Must be within plan limits

File type - Must be allowed for your plan

Content verification - MIME type must match actual content (prevents spoofing)

Storage quota - Must have available storage

Image Transformations (Business+)

Business and Enterprise plans include automatic image processing:

https://atlasforms.app/api/v1/files/{id}?w=800&h=600&fit=cover

Parameter	Description
`w`	Width in pixels
`h`	Height in pixels
`fit`	`cover`, `contain`, `fill`
`q`	Quality (1-100)
`f`	Format: `webp`, `jpeg`, `png`

Storage Management

Monitor storage usage in Dashboard → Settings.

When approaching storage limits:

Delete old submissions with files

Export and archive files externally

Upgrade your plan for more storage

Webhooks Schema Validation