Increase image size in KB

How the tool makes a file bigger

A JPG grows when it is saved at a higher quality: it keeps more of the small differences between pixels instead of rounding them away. So the tool first saves your image at the same width and height at quality 95, and if that is still under your minimum, it raises the quality, up to 100, until the file is just above it. Most small form photos pass at this step. A JPG already inside your range, with nothing else to change, is left exactly as it is.

If quality 100 is still short, only two honest routes are left: more pixels, or a format that compresses less. With Allow a larger pixel size ticked, the tool enlarges the image just enough and says so. Otherwise it shows the size that would pass, with a button to use it. And when a PNG of the same pixels would land inside your range, it offers that too, for forms that accept PNG.

It never adds filler bytes to reach a number. The last sections explain why.

How far higher quality goes

We saved small test images at quality 95, where our compressor starts, and at quality 100. The jump is large: with the same pixels, each file grew 2.2 to 3.2 times.

Quality 100 stores the same pixels more exactly. It does not make a photo sharper: if your file was already squeezed hard, its blocks stay in the bigger file too. When you still have the original photo, start from that instead.

What the tool chose for common minimums

We gave the tool the same test images and only a minimum, or a range, and let it work. When it has to raise the quality, it stops just above the minimum rather than going straight to full quality, so a 10 KB minimum gave 10.6 KB, not 21.7 KB.

Forms that set a minimum

Minimums are common on Indian recruitment and visa forms, and on online passport and visa photos elsewhere. Examples from official pages we checked on 23 October 2026:

• MSTC (recruitment): photo 20 to 50 KB at 200 x 230 pixels, signature 10 to 20 KB at 140 x 60 pixels, both sizes marked preferred, as JPG or JPEG.
• Arunachal Pradesh PSC (one time registration): photo 50 to 100 KB, signature 20 to 50 KB and scanned documents 40 to 300 KB, JPG or JPEG only.
• Indian e-Visa: a JPEG photo from 10 KB to 1 MB, with equal height and width.
• UK passport, online application: a digital photo of at least 50 KB and no more than 10 MB, at least 600 pixels wide and 750 tall.
• Immigration New Zealand, visa and NZeTA photos: 512 KB to 3.14 MB, JPG or JPEG, in portrait at 3:4. Its guide for photographers says 500 KB to 3 MB.

Rules change between notices, so check the one for your own application. For a passport or visa photo, start from the photo as your camera saved it, which is usually far above these minimums. Immigration New Zealand, for one, asks for a photo that is “natural and unaltered”, so do not enlarge a small copy for it. The UK passport photo and passport photo maker pages crop to the official shapes first.

When an image is too small to get there

Some images do not hold enough picture to reach a minimum at their size, even at quality 100. Small signatures are the usual case, because they are mostly blank paper: our 140 x 60 test signature topped out at 8.5 KB, under a 10 KB minimum.

The honest fixes are a larger pixel size if the form allows one (MSTC marks 140 x 60 as preferred, and at 166 x 71 the same signature passed at 11.5 KB), a fresh scan or photo with more detail, or a PNG if the form accepts PNG (the same signature was 14.4 KB as a PNG). Whiten the paper makes a signature smaller still, so leave it off here unless your form needs a white background. The signature resizer covers 10 to 20 KB signatures from start to finish.

If none of those works for your form, ask its helpdesk which size to use. A file padded up to the number may pass the size check, but it is still the same small image.

Why we do not pad files

Some tools reach a minimum by adding bytes the picture never uses, for example in a comment block inside the JPG. The JPEG standard allows comment blocks and leaves what is in them to the program reading the file, so a padded file opens normally and looks the same.

That is the problem: the form gets the number it asked for and none of the picture. We have not found an official notice that says why it sets a minimum or how it checks it, so we do not guess. We add bytes only by storing your picture more exactly or with more pixels, and we tell you when that is not enough.

Kilobytes are counted two ways

A kilobyte is 1,000 bytes in the SI sense and 1,024 bytes in the older binary sense, and sites use both. So the tool keeps a file above the minimum counted in 1,024s and below any maximum counted in 1,000s. With a 20 KB minimum the file is over 20,480 bytes, which passes either way.

Immigration New Zealand shows why this matters. Its photo page says 512 KB to 3.14 MB and its photographer guide says 500 KB to 3 MB. As far as we can tell these are the same limits counted two ways: 500 x 1,024 bytes is 512,000 bytes, and 3 x 1,048,576 bytes is about 3.14 million. Type 500 as the minimum and the file will be over 512,000 bytes, inside both.

Sources, checked 23 October 2026: MSTC Limited, steps for uploading images and documents; Arunachal Pradesh PSC, one time registration instructions; Indian e-Visa portal, photo and passport page requirements; GOV.UK, Photos for passports: digital photos; Immigration New Zealand, acceptable photos for a visa or NZeTA; Immigration New Zealand, Taking acceptable visa photos (PDF); ITU-T T.81 (JPEG), B.2.4.5 comment syntax (W3C copy, PDF); WHATWG HTML Standard, canvas toBlob() quality; NIST, prefixes for binary multiples.