Compress image to 1MB

Shrink a photo or image to 1MB or less for upload limits on forms, shops and communities.

This page's 1 MB preset is 1,000 KB × 1,024 = 1,024,000 bytes — between a decimal megabyte (1,000,000) and a binary one (1,048,576). If your destination counts 1,000,000 bytes, enter 976 as Target size (999,424 bytes). 1 MB is enough to keep many images lossless: the 512 × 512 NASA photo came back as a pixel-identical 575,694-byte PNG. For a 12-megapixel phone photo 1 MB gives 0.67 bits per pixel, about the density that scored SSIM 0.96 on the test photo, so full size is often possible at moderate quality.

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Three different megabytes

Nerulio multiplies the KB target by 1,024; the preset asks for 1,000 KB, so the ceiling is 1,024,000 bytes. A form that says "1 MB" may mean 1,000,000 bytes (decimal) or 1,048,576 bytes (binary). A 1,010,000-byte result passes this page's target, passes a binary limit and fails a decimal one — hence the 976 entry.

Below that ceiling the usual rules apply: the original file competes if it fits, a lossless PNG wins whenever it fits because it scores 1.0, and lossy candidates start at the level's quality and are searched down only if needed. The fixture's own PNG (791,555 bytes) and the browser's PNG re-encode (575,694 bytes) both fitted; with equal scores the smaller one won.

For a 4032 × 3024 photo the budget is 8,192,000 bits over 12,192,768 pixels = 0.67 bits per pixel. On the test photo, WebP at 0.62 bits per pixel scored 0.96, so a phone photo can usually stay at full size at a moderate quality — or at a higher quality after shrinking to about 2800 × 2100, where the budget reaches the 1.40 bits per pixel that scored 0.98.

1,024,000 bytes: 1,000 × 1,024: this page's exact ceiling.
Decimal MB: 1,000,000 bytes; enter 976 to stay under it.
Binary MB (MiB): 1,048,576 bytes; the preset is already under it.

1 MB on the NASA photo, and the budget for a phone photo

Measured with Balanced level and Auto format in Chromium 153 on 2026-09-28; the phone-photo lines are arithmetic.

Target 1 MB = 1,000 x 1,024 = 1,024,000 bytes

astronaut.png   791,555 bytes   original fits, SSIM 1.0
  PNG re-encode 575,694 bytes   SSIM 1.0, smaller   <- chosen (lossless)
  JPG q0.80      45,813 bytes   SSIM 0.9785

4032 x 3024: 8,192,000 bits / 12,192,768 px = 0.67 bits per pixel
Decimal-safe entry: 976 x 1,024 = 999,424 bytes

The chosen PNG is named astronaut-min.png; its pixels are identical to the source. At 500 KB the same photo could not stay lossless (see compress to 500 KB).

Which number to type

The destination says	Target size to enter	Largest file you get
1 MB (this preset)	1000	1,024,000 bytes
1 MB = 1,000,000 bytes	976	999,424 bytes
1 MB = 1,048,576 bytes (MiB)	1024	1,048,576 bytes
2 MB, e.g. YouTube's mobile thumbnail limit	2000 (or 1953 for 2,000,000 bytes)	2,048,000 bytes

Check the result

Check the exact byte count in the file properties; the result list shows sizes of this range in KB, e.g. "1000 KB".
If the result is a PNG, confirm the destination accepts PNG; otherwise set Output format to JPG.
For phone photos, check whether the result line says the resolution was kept.

Troubleshooting

Symptom	Likely cause	How to check	Fix
Rejected although it is "1 MB"	The destination counts 1,000,000 bytes; the result can be up to 1,024,000	Exact bytes in file properties	Enter 976 as Target size
The result is a large PNG, not a JPG	The lossless PNG fitted and scored 1.0	The name ends in `-min.png`	Set Output format to JPG if the destination needs JPG
A phone photo still misses the target	Very detailed or noisy picture needs more than 0.67 bits per pixel	Warning under the file	Allow smaller dimensions; about 2800 px wide gives 1.4 bits per pixel
A HEIC photo from an iPhone	HEIC is decoded (a decoder may be downloaded) and written as JPG, PNG or WebP	The source ends in .heic	Nothing to fix; EXIF such as the location is not written to the result

Other ways to do it

Option	When it is the better choice
Compress to 500 KB	The limit is lower or you want a lighter file for the web.
HEIC to JPG	You only need an iPhone photo as JPG and the size is not limited.
Compress a video	The file is a video, not a photo.

What this page does not cover

The preset targets 1,024,000 bytes, not 1,000,000; change the number when your destination counts decimal megabytes.
EXIF (camera, date, location) is not written, and animated images are refused.

Versions and sources

Measured on 2026-09-28 in Playwright Chromium 153 by calling src/compression.js with the options src/task/compress.js passes for the landing preset kb=1000 (src/landings.js), on tests/fixtures/astronaut.png. The YouTube 2 MB mobile thumbnail limit is from YouTube Help (checked the same day).

Official documentation used

Compress image to 1MB

Several quality and format candidates are encoded until one fits 1MB; each result is decoded again and compared (SSIM) so the best-looking one wins. You see the real file size before downloading.

Resolution is kept by default. Only if the target cannot be reached, opt in to shrinking the dimensions.

Your file is never uploaded — it is processed inside this browser.

Example

Example generated with this tool. ZIP tools show their preview; inspect the downloaded archive for every file.

Compress image

Set a size limit, then check the actual result.

How it works

Open the source file
Choose the processing mode and settings
Run, inspect the result and download

Supported formats

PNG / JPG / WebP / AVIF / HEIC → PNG / JPG / WebP — Input decoding and output encoding depend on browser support. Animated inputs are rejected; select a still frame first.

What this tool does

Auto compares actual browser codec outputs using a sampled visual metric and target-size search. Alpha-aware format selection; optional dimension reduction.

Implementation and verified quality

advanced · browser codecs / proxy SSIM candidate search. Quality qualification is in progress. Pro/Flagship quality has not been established.

Before you export

Actual device memory, storage and codec support. Tested examples are evidence, not a guarantee for every file.

Frequently asked questions

What determines the supported size?

Actual device memory, storage and codec support. Tested examples are evidence, not a guarantee for every file.

Are my files uploaded?

This tool processes the files you open on your device without uploading them. Images you explicitly attach to community posts are uploaded separately. Optional engines and models are downloaded from third parties; those requests expose connection information such as your IP address.

Will my work be saved automatically?

No. Images and editing state stay in this tab; media output can use local temporary storage. Changing language preserves your work; reloading, closing the tab, or following a link to another page can clear it.