Compress a PDF to under 1 MB.

• GST portal, proof of possession of a place of business (PDF or JPEG): You can upload PDF or JPEG files with maximum file size of upto 1 MB. You can upload maximum of 2 documents. (GST portal user guide, additional places of business)
• Indian e-Visa, the digital photograph (JPEG): Format - JPEG. Size Minimum 10 KB Maximum 1 MB. The height and width of the Photo must be equal. (Indian e-Visa, application page)

GST's note is worth reading twice: it takes at most two files, so several documents go in as one PDF. Make the combined file first (the images-to-PDF tool does this from photos), then bring it here.

• Four to six pages come out at 200 DPI, the sharpest the tool draws: they look like the original scan.
• Twelve dense pages fit at 100 DPI (952 KB in our test of a twelve-page paper in grey): clearly readable, with the smallest print soft. A rent agreement of that length is fine; twenty or more typed pages will need splitting.
• Colour usually survives up to eight pages. Beyond that, tick grey unless a colour stamp matters.
• The check counts 1,000 bytes to the KB (1 MB as 1,000 KB), the stricter reading, so a portal counting 1,024 accepts the file.

Every page is redrawn as a JPEG at the sharpest DPI that fits, from 200 down to 72, so the file is only as small as it has to be. The tool tells you the DPI it settled on when it goes below 120.

• A file that's over 1 MB with only a few pages is usually a scan at 600 DPI or full-resolution phone photos. The tool redraws those at 200 DPI and the size falls by ten times or more.
• Twenty or more dense pages is a different problem: at 1 MB that's under 50 KB a page, which is 72 DPI at best. Split by section, or export a shorter date range.
• A page that is a photograph (a site photo, a floor plan in colour) needs bytes. Keep those pages few, or supply them as JPEGs where the portal allows.
• If it misses the limit, the tool tells you the smallest it could make, so you can see whether it's close.

Photos of documents rather than a PDF? The images-to-PDF tool makes one PDF under the same limits, and an Aadhaar goes through the safe Aadhaar copy tool, which masks the number as well.