Instagram re-compresses everything. Uploading at exactly the width it wants avoids a resample you have no control over, which is most of the battle.
Use 1:1, 4:5 or 1.91:1 for the feed and 9:16 for stories. Anything else gets cropped or padded by Instagram, and it will not consult you about where.
This is the single most useful step. Instagram downscales anything wider to 1080 using its own resampling, applied on top of its compression. Arriving at exactly 1080 skips that stage entirely.
Higher than you would use for a website, because Instagram will compress again on top of yours. Starting from a cleaner file means its pass has less to damage. Going above 90 is wasted — it is discarded either way.
Send the prepared file to your phone in a way that does not re-compress it — AirDrop, a cloud folder, or a cable. Sending it through a chat app first means it is compressed before Instagram even sees it.
Instagram caps feed images at 1080 pixels wide. Upload something wider and it downscales — using its own resampling, at its own moment in the pipeline, combined with its own compression pass.
Arriving at exactly 1080 means that stage does not happen. You have already done the resize, with a good resampler, at a moment when the image was still clean. In practice this is a bigger visual difference than any export quality setting you can choose.
Of the supported feed ratios, 4:5 portrait occupies the most vertical space on a phone screen. Since the feed scrolls vertically and attention is measured in how long an image stays in view, this is a practical advantage rather than an aesthetic preference.
Square remains the safe default when the composition needs it, and landscape occupies the least screen of the three.
Instagram re-encodes every upload. There is no setting that disables it, and no export configuration that survives it untouched.
What you can control is how much damage that pass does. A file arriving at the correct dimensions, exported at a high quality, from an original that has not already been through a chat app, gives Instagram a clean source. A screenshot of a forwarded photo does not, and no amount of care afterwards recovers it.
These run in your browser on any device, so nothing is uploaded and there is nothing to install.
By pixels or percentage, aspect ratio locked, across a whole batch.
Open the toolShrink JPG and JPEG photographs with a quality slider or an exact target size.
Open the toolPortfolio and email-friendly, near-indistinguishable.
Open the toolOne setting across a whole folder, processed in parallel, downloaded as a ZIP.
Open the toolQuestions
Every answer below is present in the page source, expanded, so it can be read without opening anything.
1080 pixels wide, in one of the supported ratios: 1080 × 1080 square, 1080 × 1350 portrait, or 1080 × 566 landscape for the feed, and 1080 × 1920 for stories and reels.
Instagram re-compresses every upload, and if your file was wider than 1080 pixels it also downscaled it first using its own resampling. Resizing to exactly 1080 yourself before uploading removes that second stage and makes a visible difference.
No. Every upload is re-encoded and there is no setting to disable it. You can only give it a cleaner starting point — correct dimensions, high export quality, and an original that has not already been through a chat app.
4:5 portrait, if the composition allows. It occupies the most vertical space on a phone screen, so it stays in view longer as people scroll. Square is the safe default; landscape takes the least space.
85–90, which is higher than you would use for a website. Instagram will compress again on top, so starting from a cleaner file means less visible damage. Above 90 is discarded regardless.
Far less than dimensions. Instagram re-encodes to its own target regardless of what you send, so a carefully minimised file gains you nothing. Concentrate on the pixel dimensions and the export quality instead.
From the blog
More background from the blog.
Quality 80 is not 80% of anything. It is an index into a quantisation table. Measured on one photograph: dropping from 100 to 90 removes 77% of the file and 4.2 dB of fidelity; dropping from 40 to 30 removes 17% and costs almost as much.
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Resize before you compress. Measured on one photograph: half the width at quality 80 produced a 16.4 KB file, while full width at quality 40 produced 20.6 KB and looked far worse. The order of operations matters more than the settings.
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WebP produced a 27.0 KB file against MozJPEG's 41.1 KB on the same photograph at slightly higher measured fidelity — 34% smaller. It also produced a larger file than JPEG on random noise. The advantage is real and content-dependent.
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