Requirements-first diagnostic

File Preflight

Select a file, enter the measurable requirements supplied by the destination where you will upload it, and File Preflight inspects the file locally and compares it against what you entered. It separates what matches from what needs a fix, and recommends the right ImageToSend tool when a measurable requirement does not match.

Workspace

Check a file against your requirements

1Select your file
Loaded locally in your browser. ImageToSend does not intentionally upload your file to its servers for processing.

Drop a file here or click to select

Images (JPG, PNG, WebP, HEIC/HEIF) and other files — inspected locally

2Enter the requirements
All fields are optional. Enter only the measurable requirements the destination has stated. Decimal units: 1 KB = 1,000 bytes; 1 MB = 1,000,000 bytes.

Select a file first.

How File Preflight works

File Preflight inspects objective, measurable properties of your file locally in your browser and compares them against the requirements you enter. It reports each requirement as Matches, Needs a fix, or Check manually.

It is a diagnostic tool. It does not change your file. When a measurable requirement does not match, it points you to the ImageToSend tool that can help.

Local processing

Your file is inspected in your browser and is not intentionally uploaded to ImageToSend servers.

What it checks & what it cannot

What File Preflight checks

  • •File size against a maximum you enter (decimal bytes, KB, MB).
  • •Format against the accepted format(s) you choose.
  • •Width and height in pixels against minimum and maximum values you enter.
  • •Orientation (portrait, landscape, or square) against a required orientation.
  • •Aspect ratio against a required ratio you enter (e.g. 3:4 or 35:45).

What File Preflight cannot check

  • •Whether a third-party destination will accept the file.
  • •Government, legal, or authority acceptance.
  • •Document authenticity or identity verification.
  • •Facial/photo compliance and subject positioning rules not encoded by your entries.
  • •Visual content acceptance or malware/security certification.
How to read results

Three result states

Matches

Your file meets the measurable requirement you entered. This is a comparison against your entry, not a guarantee of acceptance.

Needs a fix

Your file does not meet a measurable requirement. File Preflight recommends the ImageToSend tool that can help, when one exists.

Check manually

ImageToSend cannot responsibly determine this. Confirm it against the destination's current instructions before submitting.

Fix routing

When to use each fix tool

File size too large

Use the Smart Image Resizer to reduce file weight toward the maximum you entered.

Format not accepted

Use the Image Converter to switch to an accepted format.

Orientation, crop, or aspect-ratio issue

Use the Document Editor to rotate, crop, or lock an aspect ratio.

Several images, one PDF needed

Use Images to PDF to combine multiple images into a single PDF.

File Preflight does not carry your file between tools. Open the recommended tool, select your file again there, apply the fix, and download the result.

Limitations

Known limitations

  • •File Preflight reads properties only — it does not modify your file.
  • •Pixel dimensions, orientation, and aspect ratio are available only for images your browser can display. For non-image files, those properties are reported as “could not be checked.”
  • •HEIC/HEIF input is decoded locally to read dimensions and is subject to a 6 MiB (6,291,456 bytes) per-file limit and a 20-second decode timeout. If decoding fails, file size and format are still reported; dimensions are not.
  • •File size uses decimal units: 1 KB = 1,000 bytes and 1 MB = 1,000,000 bytes.
  • •Aspect-ratio matching allows for normal integer-pixel rounding. A match means the image’s pixel dimensions are consistent with the ratio you entered within approximately one pixel.
  • •ImageToSend cannot enlarge an image. If a minimum width or height is not met, no ImageToSend tool can increase the resolution — use a higher-resolution source photo.
  • •“Matches” means your file matches the measurable requirements you entered. It does not mean a third-party destination will accept the file. Always confirm the destination's current instructions before submitting.

Frequently Asked Questions