How to Fix “File Type Not Supported” When Uploading Images (AVIF, HEIC & More)

Guide • 7–9 min read • Written by EasyPDF Studio

You finally have the right photo ready, click upload and then the website says: “File type not supported”. It might be an .avif, .heic or another format your phone quietly chose to save space.

In this guide we’ll walk through why this happens, which formats are “safe” everywhere, and the quickest way to convert problem files using free tools on EasyPDF Studio.

Why websites reject some image formats

Modern phones and browsers try to be clever. They save images as AVIF, HEIC or other newer formats that:

Keep file sizes much smaller
Offer better colours and details
Help pages load faster on modern sites

The problem is that a lot of portals, older systems and low-budget websites still only understand traditional formats like PNG, JPG and sometimes PDF. When they see something new, they simply say “no” instead of converting it for you.

The “safe” formats most sites accept

Most job portals, forms, government sites and older CMS tools expect one of these:

.jpg / .jpeg – best for normal photos.
.png – best for logos, screenshots and images with transparency.
.pdf – often required for documents or multi-page uploads.

If you convert your image into JPG, PNG or PDF, the error usually disappears and the upload works first time.

1. Fix “AVIF not supported” errors

AVIF is a very efficient format designed for the modern web, but support is still patchy. Some apps, older browsers and budget portals simply don’t recognise it.

Quick fix: Convert AVIF images into PNG before you upload them. PNG is almost universally accepted.

How to convert AVIF to PNG

Open the AVIF to PNG tool.
Drag your .avif file into the upload box, or tap to choose it.
Click Convert to PNG and wait a moment.
Download the new .png file and upload that instead.

The conversion runs in your browser, so your image isn’t permanently stored on a remote server. Ideal for IDs, bills and personal documents.

2. Fix “HEIC not supported” errors from iPhones

If you use an iPhone, your photos are often saved as .heic. They look perfect on Apple devices but can confuse older websites and some portals.

How to convert HEIC to JPG

Go to the HEIC to JPG tool.
Select one or more HEIC photos from your phone or computer.
Convert them to standard .jpg.
Upload the JPG versions instead of the HEIC originals.

JPG is accepted almost everywhere, so once converted, you rarely see “file type not supported” again for those images.

3. When a site asks for PDF instead of images

Some sites (especially for jobs, housing, visas or government services) don’t want separate images at all – they insist on a single PDF.

You can handle the whole process with EasyPDF Studio:

Convert awkward formats (AVIF / HEIC) into PNG or JPG first.
Open the JPG/PNG to PDF tool.
Select all the images you need (ID, payslips, bills, certificates, etc.).
Convert them into one clean PDF with each image on its own page.

If the final document is too large to upload, run it through Compress PDF to shrink the size.

4. Checklist if you still see “file type not supported”

Quick checklist before you give up:

✅ Check the file extension ends in .jpg, .png or .pdf.
✅ Try a different browser such as Chrome, Edge or Firefox.
✅ Read the small print on the form – some sites only allow certain sizes or shapes.
✅ For serious applications, convert everything to PDF using JPG/PNG to PDF.

5. The tools that help with “file type not supported”

AVIF to PNG – for modern web images that won’t upload.
HEIC to JPG – for iPhone photos causing errors.
JPG/PNG to PDF – to bundle many images into one document.
Compress PDF – for “file too large” messages.

With those four tools, you can turn almost any awkward image into a format that websites actually accept – and then package everything neatly if they prefer PDFs.

Next time the error appears…

The next time you see “file type not supported”, remember it’s not you doing anything wrong. The website is simply behind the times.

Convert the image once, save a copy in a safe format, and move on instead of fighting the same error over and over again.

Ready to fix your uploads? Start with AVIF to PNG or HEIC to JPG, depending on your file type.

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