DPI for print review, not “make JPEG lossless”
JPEG always discards some data. “Without losing quality” here means high-quality encode at a print-ish DPI, not a mathematically lossless file. Blurry free exports are usually 72–96 DPI, not a bug in JPEG itself. Agencies handing client PDFs to retouchers still get a raster — they cannot recover vectors that were flattened in the PDF.
When 300 DPI is worth Pro
Offset proofs, archival scans of small type, design handoff where screen DPI made letters look drunk. Instagram carousels rarely need this; the Presentations spoke is enough.
VPS, not a bigger tab
Sustained high-DPI raster eats RAM. Dedicated workers exist so Chrome does not die. Uploads still HTTPS, then delete.
Sample first
One representative page. If HD JPEG still artifacts on a logo, consider PNG or keep the PDF.