Post to Instagram With the Right Picture Every Time

Instagram does not accept text-only posts, and it is fussy about the pictures it does accept. PostRSS takes the picture from your feed item and prepares it — format, shape and size — before publishing, so you never have to open an image editor to get an article onto Instagram.

Instagram publishing is currently in testing while approval from Meta is pending.

What Instagram actually requires

These are Meta’s own rules for a published picture, not our preferences:

• JPEG only. PNG, WebP and GIF are refused outright.
• 8 MB maximum. Anything larger is rejected.
• Shape between 4:5 and 1.91:1. Taller or wider than that and the post is refused.
• Width between 320 and 1,440 pixels. Instagram scales this one itself.
• Reachable on a public address, because Meta fetches the file rather than receiving an upload.

The shape rule is the one that catches people out, because Instagram does not fix it for you. A banner-shaped header image from a blog post is usually far too wide, and a tall infographic is far too tall.

What PostRSS does with your picture

Every picture goes through the same steps before the post is created:

1. Taken from the feed item — the enclosure, the media element or the first image in the content.
2. Downloaded to our server, so Instagram is never sent to your site. Your server might be slow, protected, or serving a format Instagram cannot read.
3. Converted to JPEG if it is PNG, WebP or GIF — which today is most of them.
4. Cropped from the centre until the shape is inside Instagram’s allowed range. A 2000×400 banner becomes 764×400; a 400×2000 infographic becomes 400×500.
5. Resized so the width lands between 320 and 1,440 pixels.
6. Flattened onto white, because JPEG has no transparency and a transparent PNG would otherwise turn black.

Once Instagram has taken the file, the temporary copy on our server is deleted. We do not keep an archive of your pictures.

Why cropping happens from the centre

Cropping always loses something, and there is no perfect rule. Taking the middle is the choice that is wrong least often: logos, faces and products in article images tend to sit centrally, while the edges are usually background. If a particular image matters, the reliable fix is to give the feed item a picture that is already close to square.

Items with no picture at all

If a feed item has no image, there is nothing to publish — Instagram will not take a text-only post from any tool. PostRSS skips the item for Instagram, tells you why, and carries on publishing it to the other networks in your target list. Nothing is lost anywhere else.

Frequently Asked Questions

Do I need to prepare images in a particular size?
No. Anything reasonable works. A picture that is already between square and landscape will simply survive cropping untouched.

What if my site serves WebP?
It is converted to JPEG automatically. Most modern sites serve WebP, which is exactly why the conversion exists.

Does the quality drop?
Conversion uses a high JPEG quality setting. On a normal article image the difference is not visible at Instagram’s display size.

Can I set a default picture for items that have none?
That is coming. Today such items are skipped for Instagram with an explanation rather than published without an image, which Instagram would refuse anyway.

Let your pictures handle themselves

Create a free PostRSS account, connect Instagram, and stop resizing images by hand.