Instagram mockup
Rendered in your browser · nothing is uploaded
Puts your image into a 4:5 post frame and draws three lines under it: a small grey handle line, a bold line beneath it, and the caption beneath that. The three boxes in the panel fill them in that order — Site is the grey handle, Title is the bold line and takes 30 characters, which is Instagram’s own username limit, and Description is the caption, trimmed at 125 characters to stand in for the point where the feed collapses it behind a "more" link.
How to use the instagram mockup
Scale and context are what an editor takes away from you. A photograph reviewed full-screen on a laptop is a different object from the same photograph at phone width with three other posts crowding it, and the detail you thought was the subject frequently vanishes at that size. Nothing about the file changes; the viewing conditions do, and those are the conditions every viewer will actually have. Judging the frame here at the size it appears, rather than zooming in on it, is the whole exercise.
The caption fold is the second thing this catches. Instagram allows a long caption and shows only the opening of it in the feed, hiding the rest behind "more"; this frame trims at 125 characters as a working approximation of where that happens, cutting back to the last word. Instagram publishes no figure for it and the real point moves with the device and the typeface, so leave slack rather than filling the counter. What it is genuinely good for is catching an opening line that spends the visible portion on a greeting, a hashtag or a run-up. Whatever would make somebody tap "more" has to be inside the trim.
The 4:5 frame is not the shape your profile grid will show. Since January 2025 Instagram has laid the grid out in 3:4 tiles rather than squares, and it crops your post to fit. The arithmetic is easy to check and worth doing before committing to a composition. A 4:5 image cropped to 3:4 at full height loses 6.25% of its width, about three per cent from each side. A square cropped to 3:4 loses a quarter of its width, 12.5% from each side, which is enough to slice a face out of a centred portrait or cut a word off a graphic. Instagram lets you adjust the grid crop per post, so a picture whose edges matter can be repositioned rather than accepted.
Compression is the limit this preview cannot show at all. What you see here is your own file at whatever quality it already has. Instagram re-encodes uploads, and fine texture, film grain and subtle gradients degrade further than anything on this page suggests, with smooth skies and dark gradients showing banding most readily. There is no published specification for it, so the reliable advice is negative rather than precise: do not judge grain or gradient quality from a preview, and test a real upload before committing to a look that depends on either.
One documented specification matters if you publish through software rather than the app: Instagram’s content publishing API states that "JPEG is the only image format supported", and explicitly excludes extended JPEG variants such as MPO and JPS. That is an API constraint rather than an app one, and it catches people whose scheduling tool silently fails on a PNG.
What people use it for
- Seeing whether a caption still makes sense after the “more” cut
- Checking a photo against the profile it will sit under
- Showing a client the post before it is scheduled
- Checking how much a 3:4 grid crop takes off the sides of a composition
- Catching an opening line that spends the visible caption on a greeting
Questions
Because an image reviewed full-screen reads differently at phone size in a feed. Detail you thought was the subject vanishes, and a caption you thought was punchy turns out to be hidden behind "more".
4:5 portrait for the feed, which takes the most vertical space a post is allowed. The frame here is 4:5 for that reason.
Crops it to a 3:4 tile, which Instagram switched to from squares in January 2025. A 4:5 post loses about three per cent from each side; a square loses 12.5% from each side.
Yes. Instagram lets you adjust the preview per post, so a composition whose edges matter can be repositioned rather than accepted as cropped.
It is a working approximation of the feed fold, not a published limit. Instagram states no figure and the real point shifts with device and typeface, so leave a few characters of slack.
No. The preview shows your original file. Instagram re-encodes uploads and degrades fine grain and smooth gradients further than anything here suggests.
JPEG is the safe answer, and it is the only one Instagram’s publishing API accepts, extended variants such as MPO and JPS excluded. The app is more permissive, but scheduling tools frequently are not.
No. It cuts by character count, backing up to the last word, while the real fold happens by rendered width. Treat the counter as a guide with margin rather than a hard stop.
No. Everything is rendered in your browser and no file leaves the page.
Not as a file. Take a screenshot: the deliverable is your own image, and the frame is only here to judge it in.