Supported file types & formats

Upload size limits by plan

These are limits per file. Documents and archives share the other-file limit. Your total storage allowance also applies. The dashboard checks the appropriate image, video or other-file limit before uploading.

Ephemeral test accounts accept images only, up to 10 MB per image. Limits use 1 MB = 1,048,576 bytes.

File type detection

Get Pronto automatically detects file types using both file extensions and content analysis. When uploading files, you can optionally specify a MIME type to override the automatic detection:

// Override MIME type during upload
const result = await client.files.upload(file, {
  mimeType: "image/png"
});

Images

Static and animated image formats

Videos

Common video formats

Documents

Text-based formats

Archives

Compressed file formats

Image defaults and fallback behaviour

• Format: Without a format parameter, the delivery URL's extension selects the output format. Keeping the original extension keeps the original format. A format parameter overrides the extension.
• Automatic format: format=auto lets Get Pronto choose an efficient output format. SVG and BMP originals are passed through without transformation. Keep the original extension in the URL; do not use .auto. The choice does not depend on the visitor's browser or Accept header.
• Quality: Encoding defaults to 80 when quality is omitted. q=auto starts with a quality for the output format and adjusts it for simple graphics or transparency. It does not target a file size or guarantee a compression ratio. GIF output does not use the quality setting. With no transformations requested, the original is served without re-encoding.
• Dimensions: Resizes never enlarge an image beyond its source dimensions. Supply one dimension to preserve its aspect ratio. Responsive sizing uses explicit width candidates in srcset and your layout's sizes value; the API does not accept w=auto or h=auto.
• Animation: Animated GIF/WebP sources retain animation when the output is GIF or WebP. If the requested output cannot preserve animation, the original is returned and the requested transformations are not applied.
• Transparency: WebP can retain transparency. JPEG cannot: transparent pixels are composited onto white during JPEG conversion.
• SVG and BMP: Get Pronto does not encode these output formats. Requests targeting them return the original without applying transformations. To rasterize an SVG, explicitly request a writable format such as PNG or WebP.
• Transformation allowance: When the transformation quota prevents generating a new variant, delivery falls back to the original. Existing stored variants can still be served, subject to bandwidth limits. Fallbacks may have a different format or dimensions from those requested.

Automatic options are opt-in. A given automatic URL does not vary by visitor, allowing it to be cached. Automatic format and its explicit equivalent share a stored variant when all other options match. Automatic quality is a separate variant from numeric quality.

// Explicit WebP conversion
const webpUrl = await client.images
  .transform(fileId)
  .format("webp")
  .toURL();

// Automatic format and quality
const optimizedUrl = await client.images
  .transform(fileId)
  .format("auto")
  .quality("auto")
  .toURL();