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

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 saved in the background.

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

Why websites reject some image formats

Modern phones and browsers try to save space, so they use newer formats like AVIF and HEIC. These give you:

• Smaller file sizes for the same quality
• Better colours and support for transparency
• Faster loading on modern websites and apps

The catch: lots of older systems and platforms still only understand traditional formats like PNG and JPG. When they see something new, they simply show an error instead of converting it for you.

The “safe” formats most sites accept

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

• .jpg / .jpeg – best for photos
• .png – best for logos, screenshots and images with transparency
• Sometimes .pdf – especially for multi-page documents

If you convert your images into JPG, PNG or PDF, upload errors usually disappear.

1. Fix “AVIF not supported” errors

AVIF is a very efficient format, but it’s still new. Many older sites and low-budget platforms don’t support it yet.

How to convert AVIF to PNG

• Open the AVIF to PNG tool.
• Drag your .avif file into the box or tap to select it.
• Click Convert to PNG.
• Download the new .png file and upload that instead.

The conversion runs in your browser, so your images aren’t permanently stored on a remote server.

2. Fix “HEIC not supported” errors from iPhones

If you use an iPhone, your photos are often saved as .heic. They look fine on Apple devices, but many websites still don’t recognise the format.

How to convert HEIC to JPG

• Go to the HEIC to JPG tool.
• Select one or more HEIC photos from your device.
• Convert them to standard .jpg.
• Upload the JPG versions to the website or form.

JPG is accepted almost everywhere, so once your photos are converted, upload problems usually disappear.

3. When a site prefers PDF instead of images

Some portals (especially for jobs, housing, visas or government services) tell you to upload a single PDF instead of separate photos.

You can complete the whole flow using EasyPDF Studio:

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

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

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

Run through this quick checklist:

• ✅ Make sure the file ends in .jpg, .png or .pdf.
• ✅ Try a different browser (Chrome, Edge, Firefox) if the site is old.
• ✅ Check the site’s help text – some have strict size limits or aspect ratios.
• ✅ If it’s for a formal application, convert everything to PDF using JPG/PNG to PDF.

Which EasyPDF Studio tools help with this?

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

Related guides

• What Is AVIF (and How to Convert It to PNG When Sites Don’t Accept It)
• Simple Checklist to Fix Image Upload Problems (Format, Size & Quality)
• JPG vs PNG vs WebP vs AVIF: Which Image Format Should You Use?

With these tools together, you can turn almost any awkward image into a format that websites accept without complaints.

Next time you see “file type not supported”, you’ll know it’s not your fault – the website is just behind the times. Convert the file once and move on.

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