Quick answer: For email proofs of marketing PDFs, use 150 DPI and JPEG quality around 90%. A single letter-size page exports at roughly 1.3 MB, which fits most inbox limits. Switch to 300 DPI only when the client must judge fine type or small product photos.
- 150 DPI keeps a one-page proof near 400–700 KB. Good for quick client OK by email.
- 300 DPI on letter size lands near 2550×3300 pixels (about 1.5–2.5 MB per page).
- 600 DPI or PNG format for archival scans, line art, and small text that must stay crisp under a loupe.
- Upload the original press-ready PDF for production. JPG or PNG exports are for review only.
Why print teams export PDF pages as JPG
Email clients show JPG inline. PDF attachments often need a separate app. Social posts accept images but not always PDF. Client portals sometimes ask for flat JPG uploads. A JPG proof answers "does this look right?" without handing over the production file.
On our prepress desk we see this daily: a restaurant owner emails a menu PDF, the client replies on a phone, and nobody opens the attachment. Export page 1 at 150 DPI, send the JPG, and approval comes back in minutes. When the job is approved, the owner uploads the original PDF through our file uploader for the actual print run.
DPI settings and file size math
DPI here means pixels per inch when the PDF page is rasterized. Higher DPI means sharper type and photos. It also means larger files and slower email delivery.
| DPI setting | Best for | Letter page (8.5×11″) pixels | Typical JPG size (1 page, quality 90%) |
|---|---|---|---|
| 150 DPI | Email proof, quick client OK | 1275 × 1650 | 400–700 KB |
| 200 DPI | Balanced screen review | 1700 × 2200 | 800 KB–1.2 MB |
| 300 DPI | Fine type, photo detail check | 2550 × 3300 | 1.5–2.5 MB |
| 600 DPI | Archival scans, fine line art, loupe-level detail | 5100 × 6600 | 4–8 MB |
A 12-page sell sheet at 300 DPI can produce a ZIP near 20–30 MB. For stakeholder review, 150 DPI on each page often keeps the bundle under 10 MB. Planning figures only. Actual size depends on photos, vectors, and JPEG quality slider.
JPG or PNG: which one for a print proof?
JPG uses lossy compression, so file sizes stay small but fine edges soften slightly - fine for photo-heavy flyers and postcards. PNG is lossless, so small type, line art, and logos stay pixel-perfect, at roughly 2–4× the file size of a comparable JPG. According to the standard definition of DPI, resolution measures dot density regardless of format - the format choice only affects compression, not sharpness at a given DPI. Use PNG when a client needs to zoom into small text on a scanned contract or a technical line-art proof; use JPG for everything else to keep email attachments light.
Three workflows we see on press week
Listing flyer proof before a postcard order
Maria runs open houses in Broward County. Her designer sends a 2-page PDF: front with photos, back with specs. Maria exports page 1 at 150 DPI, emails the JPG to the seller, and gets a same-day OK. She then orders 500 4×6 postcards, double-sided, through our postcard printing for about $53 (roughly 11¢ each) and uploads the original PDF, not the JPG.
Menu update for social, not for the press
A café owner refreshes a lunch menu PDF every Monday. Instagram wants a square image, not a PDF attachment. Export the menu page at 200 DPI, crop in any phone app, and post. When trays need reprinting, the owner still submits the vector or high-res PDF for production.
Multi-page sell sheet for internal sign-off
An event planner has a 16-page sponsorship deck. Stakeholders use Slack on laptops and phones. Convert the full PDF at 150 DPI, download the ZIP, and drop individual page JPGs into the channel. Each approver marks up their page. Once everyone signs off, production files stay as PDF for the flyer print order - 500 double-sided 8.5×11 flyers run about $125 (25¢ each).
JPG proof vs press-ready PDF
| Use case | Send this | Why |
|---|---|---|
| Client approval by email | JPG at 150–200 DPI | Small file, displays inline, fast reply |
| Commercial print order | Original PDF | Keeps vectors, fonts, and full resolution |
| Color accuracy check before press | PDF proof + our DPI checker | Browser JPG is RGB; press uses CMYK |
How rasterization keeps type readable
A PDF stores text, fonts, and vector art in a structured format. Converting to JPG draws that content onto a pixel grid at the DPI you pick. This tool uses the same class of rendering engine trusted in modern browsers. At 300 DPI, 8 pt body copy on a flyer usually stays crisp enough for a proof. It is still a flat image, not editable text.
For brochure and booklet jobs, pair JPG previews with a vector or 300 DPI PDF for production. Need help? Use the free upload option above or email support@55printing.com.
Frequently asked questions
What DPI should I use when converting a PDF to JPG for a print proof?
Use 150 DPI when the goal is a fast email proof. A letter page lands near 1275×1650 pixels and often stays under 700 KB at 90% JPEG quality. Use 300 DPI when the client must judge fine type, small logos, or product photos. A letter page at 300 DPI is about 2550×3300 pixels and roughly 1.5–2.5 MB. For the actual print order, upload the original PDF to 55 Printing, not the exported JPG.
How do I convert a multi-page PDF to separate JPG files?
Upload the PDF and click Convert to JPG. Single-page files download as one JPG. Multi-page files export one JPG per page (named with the page number) and bundle into a ZIP automatically. A 24-page booklet at 150 DPI often produces a ZIP between 8 MB and 15 MB depending on photo coverage. Process one PDF per minute under the fair-use limit.
Can I convert a PDF to PNG instead of JPG?
Yes. Pick PNG from the Output format menu before converting. PNG is lossless, so small type, thin rule lines, and logo edges stay perfectly sharp with no compression artifacts. The tradeoff is size: a PNG page typically runs 2 to 4 times larger than a JPG at the same DPI. Use PNG for scanned contracts, line-art proofs, or any page a client will zoom into on screen. Use JPG for photo-heavy flyers and postcards where a smaller email attachment matters more than pixel-perfect edges.
Should I upload the JPG or the original PDF for printing?
Always upload the original press-ready PDF when placing a print order. JPG exports are for proofs, client approvals, and platforms that do not accept PDF files. A PDF keeps vector data, embedded fonts, and full resolution. Submitting a JPG for production increases the risk of soft edges, color shift, and missing font details on a 500-copy flyer or 1,000-card postcard run.
Will brand colors in the JPG match the printed piece?
The browser renders in RGB. Commercial presses print in CMYK. A JPG proof is useful for layout, photo placement, and type size. It is not a contract color match. For color-critical jobs, request a PDF proof through our proof tools and use our print templates before upload.
Are my PDF files uploaded to your servers?
No PDF content is uploaded for conversion. Processing runs locally in your browser. After a successful export, only lightweight anti-abuse metadata is sent to enforce the one-conversion-per-minute fair-use policy. Your file contents stay on your device unless you choose the free human-help upload form above.
Why is there a one-conversion-per-minute limit?
The limit blocks automated abuse so the tool stays free and fast for real users. After each successful conversion, wait about 60 seconds before processing another PDF. If you need batch conversion for a production workflow (dozens of files per day), contact support@55printing.com. Our prepress team can handle high-volume conversion at no charge through the upload form.
Can I convert a scanned PDF to JPG?
Yes. Scanned PDFs are already image-based. Each page exports to JPG at the DPI you select. For scanned contracts or archival pages, 300 DPI at 100% JPEG quality preserves the most detail. Expect larger files: a single scanned letter page at 300 DPI is often 2 MB or more depending on scan density.
What if my PDF is password-protected or will not convert?
Encrypted PDFs cannot be opened in the browser engine. Remove the password in your PDF app first, or use the free human-help upload above. Very large pages may scale slightly to respect browser canvas limits (8192 pixels on the longest side). Lower DPI improves stability on phones and low-memory devices.