Short answer: no lab we checked requires 300 DPI to upload. Published floors run from 75 DPI at Printful to 150 PPI at One Vision Imaging. Nations Photo Lab publishes 125 DPI. Mpix accepts 100 PPI. Here are seven labs' own numbers, linked to their own help pages, checked November 1, 2026.

By Team DPI Converter · Photo resolution analysts · Every number linked to a dated source · Last updated November 1, 2026

Who we are / what we are not: We build free image-resolution tools at DPI Converter Online. We are not a print lab, not a broker, and not affiliated with any lab compared here. We do not sell prints. Every number below is either quoted from a lab's own help page with a link, or arithmetic from those published numbers.

What minimum DPI does each photo lab publish?

We read each lab's own help pages. Every figure below comes from the lab itself. We list the published floor first, then the published target. Where a lab publishes no floor, we say so. Access date for every page: November 1, 2026.

Published upload minimums and quality targets, as stated by each lab. DPI and PPI are the labs' own wording.
Lab Published minimum (floor) Published target Formats & notes
Nations Photo Lab 125 DPI ("125 dpi minimum resolution - 300 dpi maximum") 300 DPI (published maximum) JPG, PNG, flattened TIFF; sRGB; 8-bit; 40 MB per file online; no size cap in ROES
Mpix 100 PPI implied by its minimum chart (4x6 = 400×600 px) 250–300 DPI ("Mpix printers output at 250 ppi") JPEG, PNG; RGB only; no maximum resolution required
Bay Photo No hard floor published. Good-print table drops to 200×300 px at 4x6 (50 PPI, our arithmetic) "200-300 PPI at print size" ideally JPG, PNG, TIFF; 8-bit; sRGB or Adobe RGB; Baseline Standard JPG only
Printful (paper) 75 DPI accepted ("minimum accepted DPI for paper products is 75") 300 DPI recommended PNG, JPEG; sRGB; up to 200 MB / 20,000×20,000 px
Printful (most products) 150 DPI minimum; 300 DPI for phone cases and stickers 150–300 DPI; "best not to exceed 300 DPI" Apparel and other non-paper products
Shutterfly No PPI floor published. Per-size pixel recommendations instead 300 PPI "ideal" (4x6 = 1200×1800 px) JPG, PNG, BMP; 8-bit RGB/sRGB; 150 MB and 100 MP upload caps
WhiteWall (photo books) Warning below 125 ppi (red), below 175 ppi (yellow). Wall art floor: 700×700 px 300 dpi for close viewing; printer output 180–400 dpi by product JPG, PNG; 50 MB per book file; RAW must be converted
One Vision Imaging (via Zenfolio) 150 PPI ("minimum required image resolution") 300 PPI recommended Miller's family labs (MPIX, MpixPro, MILLERS) publish a 100 PPI floor; Miller's photo books require 250 PPI
Table 1. Published minimums, verbatim or paraphrased from each lab's help pages. Sources and dates at the end of this article.
75 DPI The lowest published acceptance floor we found: Printful accepts paper product files at 75 DPI, while recommending 300 for quality. According to Printful, "the minimum accepted DPI for paper products is 75."

Why don't photo labs require 300 DPI?

Because a hard floor blocks orders. Labs set floors low, then warn. Nations Photo Lab says it in its own FAQ: below 125 PPI, "Yes, you can still place your order." The print may look soft. The order still ships.

The 300 figure describes close viewing, not acceptance. Bay Photo says files should "ideally" sit at 200-300 PPI at print size. Shutterfly calls 300 PPI "ideal." Printful recommends 300 for paper. None of those pages turn the recommendation into a rule.

The floors exist to catch broken files, not soft ones. WhiteWall hides print sizes its configurator cannot produce. Mpix warns when an image cannot fill the ordered size. Printful's Smart Image Tool doubles the DPI of files between 38 and 74 DPI before upload, and between 75 and 149 DPI for paper products.

No maximum, mostly Mpix states plainly: "We do not require a maximum resolution for the images you upload." Nations Photo Lab is the exception in this group: it publishes a 300 DPI maximum.

Do labs mean DPI or PPI when they state a minimum?

They mix the terms. Nations Photo Lab writes "125 dpi minimum" on one page and heads its pixel chart "125 PPI Minimum Requirement" on another. Both describe the same thing: pixels of your file divided by inches of print.

WhiteWall resolves the debate in one line. On the PPI-versus-DPI question it says "a distinction between PPI and DPI is hardly relevant" in practice, so it uses DPI everywhere. Mpix separates them cleanly: PPI measures your file, DPI measures ink dots on paper.

Practical rule for shoppers:

  1. Ignore the unit label on the lab's page.
  2. Read your file's pixel width and height.
  3. Divide by the print size in inches.
  4. Compare that number with the lab's floor. The math does not care about the label.

What pixel dimensions do labs require for common print sizes?

Four labs publish raw pixel numbers. These are their figures, not ours. Shutterfly's column is a recommendation, not a floor, because Shutterfly publishes no floor.

Published pixel dimensions by print size. Minimum = floor or acceptance chart. Recommended = quality target.
Print size Nations (125 PPI chart) Mpix minimum Bay Photo good-print minimum Shutterfly recommended
4 x 6500 x 750400 x 600200 x 3001200 x 1800
5 x 7625 x 875500 x 700250 x 3501500 x 2100
8 x 101000 x 1250800 x 1000400 x 5002400 x 3000
16 x 202000 x 25001600 x 20001200 x 15004800 x 6000
Table 2. Published numbers. The gap between floors and targets is the decision you still have to make: acceptable, or sharp?
Published upload floors by lab (DPI or PPI, as the lab words it) Published upload floor (DPI/PPI) 0 50 100 150 Bay 4x6 50 PPI (200x300 px) Printful paper 75 DPI Mpix 100 PPI (400x600 px 4x6) Nations 125 DPI (published max: 300) WhiteWall bk 125 ppi (red warning line) Printful 150 DPI (most products) One Vision 150 PPI Floors as published by each lab, November 1, 2026. Bay Photo figure = 200x300 px at 4x6 (our arithmetic). Shutterfly publishes no floor, so it is not plotted.
Published upload floors differ by a factor of three across seven labs. None of them is 300.

What happens if your file is below the lab minimum?

Each lab handles it differently. Here is what its own documentation says:

  • Nations Photo Lab: an orange triangle appears next to the photo. The warning shows your crop's DPI and estimated quality. You can keep the file and order anyway. Below 125 PPI, prints "may appear soft, blurry, or grainy, especially when viewed up close."
  • Mpix: "Our software will notify you if your image does not meet our minimum requirement." The alert fires when the file cannot fill the chosen size.
  • Shutterfly: displays a warning during project creation when resolution is too low for the selected product size.
  • WhiteWall: hides print sizes that cannot be produced from your file. For photo books it shows yellow below 175 ppi and red below 125 ppi.
  • Printful: shows print quality warnings at upload, and its Smart Image Tool can double the DPI of files in the 38-74 DPI range (75-149 for paper) to reach the minimum. Printful says the tool "can't adjust unwanted image features like blurriness/pixelation."
  • Bay Photo: publishes no blocking threshold. It advises viewing files at 100% in an image editor, which it says "will give you an excellent representation of how the file will print."

What if a lab publishes two different minimums?

Expect conflicts. Nations Photo Lab documents three different numbers across its own help center:

  1. 125 DPI — the ordering page and blog prep guide: "125 DPI minimum and 300 DPI maximum."
  2. 150 DPI — the file-organization doc: "Low-resolution files (under 150 dpi) may appear pixelated in print."
  3. 300 DPI — the same doc and the album help page list 300 DPI as the requirement for best results.

How to read this: 125 is the acceptance floor, 150 is the quality warning line, and 300 is the target. Treat the floor as the pass/fail line. Treat everything above it as your quality margin. When you order, check the page for that specific product, because floors vary by product at several labs. Miller's photo books, for example, require 250 PPI even though Miller's prints accept 100 PPI.

250 PPI vs 100 PPI Same lab family, different products. Miller's photo books require 250 PPI; Miller's photographic and metal prints accept 100 PPI, according to Zenfolio's support documentation.

How do I check my photo before uploading?

  1. Day 1, minute 1: Write down the lab and the exact print size in inches.
  2. Minute 2: Read your file's pixel width and height. On Windows, right-click the file, Properties, Details. On Mac, Finder, Get Info, More Info.
  3. Minute 3: Divide pixel width by print width, and pixel height by print height. The smaller number is your effective PPI at that size.
  4. Minute 4: Compare it with the lab's floor in Table 1. Above the floor: acceptable. Below: reorder at a smaller size or use the original file.
  5. Minute 5: If you sit within 20% of the floor, order one small proof before the full run.

Or skip the arithmetic and use the checker below. It runs the comparison against all seven labs at once.

Which lab should I choose based on my file?

Match the file you have to the floor the lab publishes:

  • Phone photo, standard sizes (4x6, 5x7): any lab in Table 1. Even a 4000×3000 phone file gives 667 PPI at 6 inches wide (our arithmetic). Quality limits here come from cropping and compression, not lab floors.
  • Cropped or screenshot files (roughly 1-2 MP): Printful paper (75 DPI) and Bay Photo's good-print range have the lowest floors. Nations accepts down to 125 PPI. Shutterfly has no published floor, but its 300 PPI ideal means expect warnings at 8x10 and up.
  • Large wall art (16x20 and up): check the floor at print size, not at 4x6. A 2000×2500 file meets Nations' 125 PPI chart for 16x20, but sits at half Bay Photo's 250 PPI column and far below Shutterfly's 4800×6000 recommendation.
  • Photo books: WhiteWall warns below 175 ppi; Miller's books require 250 PPI. Cropping inside templates lowers effective PPI, so start above the floor.
  • Print-on-demand merch (mugs, cases, stickers): Printful requires 300 DPI for phone cases and stickers, and 150 DPI for most other products.

Free tool: check your photo against all 7 labs

Enter your photo's pixel size and your print size. The checker returns your effective PPI, then compares it with every published floor in Table 1.

Lab DPI Checker

Enter your numbers to see the comparison.

Runs entirely in your browser. Nothing is uploaded. Want the general math? Try our full DPI calculator and DPI converter.

Video transcript summary: The video opens with the 75 DPI floor at Printful and the 125 DPI floor at Nations Photo Lab, walks the seven-row comparison table, demonstrates the Lab DPI Checker on a cropped phone photo, and shows what each lab's warning dialog actually looks like. Full transcript to be added at publish.

FAQ

What DPI do photo labs require?

Published minimums span 75 to 150 DPI across the seven labs we checked. Nations Photo Lab publishes 125 DPI. Mpix accepts 100 PPI. Printful accepts paper files at 75 DPI. One Vision requires 150 PPI. No lab we checked requires 300 DPI to upload. 300 is a quality target, not an upload rule.

Is 300 DPI required for photo prints?

No. Several labs recommend 300. Shutterfly calls 300 PPI ideal. Bay Photo says ideally 200-300 PPI at print size. Printful recommends 300 for paper products. None of them publishes 300 as an acceptance floor. Treat 300 as your target and the published floor as the line you must clear.

What happens if my photo is below the lab's minimum?

It depends on the lab. Nations shows a warning and still lets you order. Mpix alerts you when the image cannot fill the size. WhiteWall hides impossible sizes and shows yellow or red warnings for books. Shutterfly warns during project creation. No lab fixes missing detail: the printer enlarges what you sent.

What DPI does Nations Photo Lab require?

125 DPI minimum and 300 DPI maximum, per its ordering page and prep guide. Its low-resolution warning triggers below 125 PPI at the chosen size. A separate Nations document advises using 300 DPI and says files under 150 DPI may print pixelated. Check the page for the product you are ordering.

Does Mpix require 300 DPI?

No. Mpix publishes a minimum chart: 400 x 600 pixels for a 4x6, which works out to 100 PPI at that size. Mpix says its printers output at 250 ppi, recommends 250-300 DPI uploads, and requires no maximum resolution.

What resolution do photo labs require for photo books?

WhiteWall flags book images below 175 ppi as risky and below 125 ppi as severely impaired. Miller's photo books require 250 PPI per Zenfolio's support docs. Cropping inside a template reduces effective PPI, so start well above the floor.

Can I just change the DPI number on my file?

You can change the embedded number, but not the pixels. Resaving a small file with a 300 DPI tag adds zero detail. The lab divides your pixel count by the print size either way. Fix the file, not the metadata. We show the steps in our guide to changing DPI of an image.

Next steps: your one-week print-prep plan

  1. Day 1 (Nov 1, 2026): Pick the lab. Open its help page in Table 1 and read the floor for your product.
  2. Day 2: Run every candidate photo through the checker above. Note the effective PPI for each print size.
  3. Day 3: Sort files into three buckets: comfortably above the floor, near the floor, below the floor.
  4. Day 4: For near-floor files, order one small proof. For below-floor files, order a smaller size or pull the original from camera storage.
  5. Day 5: Inspect the proof at the distance the final print will hang. Judge sharpness, not color.
  6. Day 6: Place the full order for files that passed the proof.
  7. Day 7: Save this page's checker result for the next order. Re-check whenever you crop differently.
The decision you still have to make The floor tells you what the lab will accept. Only you know whether softness at your real viewing distance matters. Prove it with one small print, not a full order.

Our expectations for the next year (opinion, not sourced): more labs will publish pixel-level tables like Nations' and Bay Photo's, because automated checks (WhiteWall's configurator, Printful's Smart Image Tool) already depend on them. We expect at least one major consumer lab to publish an explicit PPI floor within the next two quarters, closing the gap Shutterfly currently leaves open. Treat this paragraph as our opinion, not as an industry forecast.

Sources

  1. Nations Photo Lab. "How to Order Prints." nationsphotolab.com/pages/how-to-order-prints. Accessed November 1, 2026.
  2. Berman, Jenna. "How to Prep Your Files for the Best Printing Experience." Nations Photo Lab blog, September 28, 2026. nationsphotolab.com/blogs/product-news-and-info/prep-your-files-for-the-best-printing-experience.
  3. Nations Photo Lab. "Understanding the Low-Resolution Warning: Why We Recommend Images of at Least 125 Pixels per Inch." Nations Photo Lab Zendesk, undated. nationsphotolab.zendesk.com/hc/en-us/articles/360002280794. Accessed November 1, 2026.
  4. Nations Photo Lab. "Photo or Image File Organization." Zendesk, undated. nationsphotolab.zendesk.com/hc/en-us/articles/40139012793883. Accessed November 1, 2026.
  5. Nations Photo Lab. "Image Resolution Guidelines." nationsphotolab.com/pages/guide-image-resolution. Accessed November 1, 2026.
  6. Mpix. "Requirements to upload your photos." mpix.com/help/uploading-photos. Accessed November 1, 2026.
  7. Mpix. "How to prepare your photos." mpix.com/help/topics?id=3. Accessed November 1, 2026.
  8. Mpix. "How to Upload Photos for High-Quality Prints." mpix.com/learn/guide-to-uploading-photos. Accessed November 1, 2026.
  9. BayPhoto. "What image file formats are accepted?" Updated April 14, 2025. support.bayphoto.com/hc/en-us/articles/40335215683859. Accessed November 1, 2026.
  10. Bay Photo Lab. "Image file specifications." art.bayphoto.com/image-file-specifications. Accessed November 1, 2026.
  11. BayPhoto. "MetalPrints FAQs." Updated July 13, 2026. support.bayphoto.com/hc/en-us/articles/40359849071379. Accessed November 1, 2026.
  12. Printful. "Create the perfect wall art print file." printful.com/create-digital-print-file. Accessed November 1, 2026.
  13. Printful. "Create the perfect DTG file." printful.com/creating-dtg-file. Accessed November 1, 2026.
  14. Printful Help Center. "What is DPI, resolution and actual print file size?" help.printful.com/hc/en-us/articles/50264010605457. Accessed November 1, 2026.
  15. Printful Help Center. "What does the Smart Image Tool do?" help.printful.com/hc/en-us/articles/360014010760. Accessed November 1, 2026.
  16. Shutterfly. "Photo Prints Guide: Sizes, Finishes, Pricing & FAQs." August 10, 2026. shutterfly.com/ideas/everything-you-need-to-know-about-shutterfly-photo-prints.
  17. Shutterfly. "What Makes Shutterfly Photo Quality Stand Out." May 20, 2026. shutterfly.com/ideas/what-to-know-about-shutterflys-photo-print-quality.
  18. Shutterfly Canada. "Unable to upload photos." Updated June 15, 2023. support.shutterflycanada.ca/hc/en-ca/articles/9370482181531. Accessed November 1, 2026.
  19. WhiteWall Service. "15 - File requirements." Updated March 18, 2026. service.whitewall.com/hc/en-us/articles/4411236151313. Accessed November 1, 2026.
  20. WhiteWall Service. "What is the optimal format for my image file?" Updated March 16, 2026. service.whitewall.com/hc/en-us/articles/213270909. Accessed November 1, 2026.
  21. WhiteWall Service. "How big can my image file be?" service.whitewall.com/hc/en-us/articles/213812765. Accessed November 1, 2026.
  22. Zenfolio Support. "Having Sufficient Image Size for Printing." support.zenfolio.com/hc/en-us/articles/7432691669011. Accessed November 1, 2026.
  23. Arithmetic on this page: effective PPI = pixels ÷ print inches. All derived figures (for example Bay Photo's 50 PPI at 4x6) are computed from published pixel numbers, not estimated.