ContextCleaner: see every entry in the Windows 11 right-click menu, and which app added it — on the Microsoft Store.

Last updated:

Guided workflow variation

A preflight check for client PDFs,run on this PC.

Open a client PDF and ProofSlip reads it on your Windows PC, grades every finding, and gives one verdict: PASS or FAIL. Export that result as a one-page PDF or an HTML report to send back with the job.

ProofSlip covers the technical half of preflight on Windows: fonts, page geometry, color spaces and placed-image ppi, with a report you can forward. It never edits the file.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Full ProofSlip overview
One-time purchase No telemetry Local-first

windows · one-page pass or fail · original never written · nothing uploads

If this sounds like your week

Client files arrive with faults nobody sees on screen.

A customer emails artwork that seems flawless in a viewer. On press it emerges that a typeface was never embedded, a product shot came from the client's online shop at a fraction of the density it needs, and the background stops exactly at the edge. Small print and copy shops, and the freelancers who supply them, usually catch this by opening the document and poking at property dialogs one at a time, often after the job is already scheduled.

Where tooling usually breaks

The usual routes cost money, privacy, or an afternoon.

Professional preflight suites are priced for prepress departments, frequently as a subscription layered on a full editor. Online services that charge nothing want the artwork uploaded to someone else's server, which some customers and some shop policies rule out. Doing it manually means hunting through menus, measuring pictures with a calculator, and still having nothing tidy to send the customer when something is wrong.

Where ProofSlip lands

One verdict, every finding graded, a report to send.

ProofSlip opens the document read-only through the Windows file picker and inspects it locally. Findings are graded FAIL, WARN or INFO under a single verdict, so a missing typeface or a coarse photograph stands out at once, while RGB and thin bleed appear as warnings to weigh against the printer's spec sheet. Select any row for its detail, then export a one-page PDF or an HTML report as a new file. The source is never touched.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Learn more about ProofSlip

windows · one-page pass or fail · original never written · nothing uploads

What you get

Feature highlights

One verdict, every finding graded

a single PASS or FAIL at the top, with each finding marked FAIL, WARN or INFO and the pages it affects, so the warnings are read as well as the verdict.

Fonts with the pages that use them

every font with its type, subset tag and embedding, and a FAIL when a font that paints visible text is not embedded, including the standard 14 base fonts.

Image ppi where it is placed

effective ppi for every placement, measured from the page itself and sorted lowest first, failing color and grayscale images below 150 ppi and 1-bit images below 300.

Trim, bleed and page size

size from the trim box or media box, named sizes such as A4 and Letter, and bleed on each side in millimeters, with a warning under 3 mm.

Color spaces page by page

Gray, RGB, CMYK, Lab and spot colors with their pages, every spot name and the output intent; RGB and Lab are warnings, and nothing is converted.

A report you can send, and an untouched original

a one-page PDF report or an HTML report saved as a new file, while the source PDF is opened read-only, never written, and nothing uploads.

Especially when

  • Check a client PDF for unembedded fonts, low-resolution images, RGB color and missing bleed on a Windows PC without uploading it
  • See the effective ppi of every placed image in a PDF instead of measuring each one by hand
  • Send a client a one-page report that names each problem and the pages it affects
  • Preflight print files without paying for professional prepress software or a PDF editor subscription

Who benefits

Real-world scenarios

Counter staff at a small copy shop

A customer emails a twelve-page brochure an hour before closing and wants it printed first thing tomorrow. Whoever is at the counter needs to know whether it can join the queue or has to go back.

ProofSlip shows FAIL with one font that is not embedded on pages 3 to 5. The staff member exports the one-page PDF report and attaches it to the reply, so the customer sees the font name and the pages before exporting again.

A freelancer checking before sending

A freelance designer exports a poster from a layout app and wants to know, before emailing the printer, whether any placed photo is too coarse at the size it prints.

The Images table lists every image with the lowest effective ppi first. One photo shows a WARN at 212 ppi, and the designer decides with the printer's spec sheet in hand whether to keep it or place the larger original.

A shop that will not upload client files

A print coordinator handles artwork for clients who ask that their files never go to third-party websites, which rules out the online checkers the team had been using.

ProofSlip runs in a Windows app container with no network capability, reads only the file picked in the Open dialog, and writes only the report the coordinator saves. The client's PDF stays on that PC throughout.

Deep dive

What a preflight check covers, and what ProofSlip leaves to you

Preflight in two halves. A full preflight asks two kinds of question. The first is technical: can a print workflow read this file and reproduce it at the intended quality? Are the fonts inside the file, are the images dense enough at the size they print, which color spaces does it use, and how are the page boxes set? The second is about the job: is this the size that was ordered, is there enough bleed for this product, does the printer accept RGB? ProofSlip answers the first half and lays out the facts you need for the second.

What it reads. For every page it records the size from the trim box when one exists, otherwise the media box, and names common sizes such as A4, Letter or a US business card. It lists trim and bleed boxes when the file has them and measures the bleed on each side. It lists every font with its type, whether it is embedded, and the pages that use it. It measures each image where it is placed and reports the effective ppi. It counts the color spaces in use, names any spot colors, and shows the output intent.

How the verdict is decided. The file fails when a font that paints visible text is not embedded, when a color or grayscale image is placed below 150 ppi, when a 1-bit image is below 300 ppi, or when content on a page cannot be read. Warnings cover images from 150 to 299 ppi, 1-bit images from 300 to 599 ppi, RGB or Lab color, mixed page sizes, a trim box with no bleed box, and bleed under 3 mm. Notes cover spot colors, a missing output intent, rotation and placements that could not be measured. These limits are fixed in this version, so compare them with your printer's spec sheet. If the spec asks for 300 ppi, read every image warning as a failure for that job.

What a PASS does not tell you. A PASS means no failing finding, nothing more. A typical office export with no trim box and no bleed passes with an RGB warning and a no-trim-box note, so always read the warnings. ProofSlip does not render pages, so it cannot see whether artwork actually reaches into the bleed, whether text sits too close to the trim, or how ink will build up. It does not check overprint, transparency, hairlines, rich black or total ink, and it does not validate PDF/X conformance; a declared PDF/X version is shown as what the file declares.

What it never does. ProofSlip does not embed fonts, convert color, resample images or flatten anything. The PDF is opened read-only, never written, and a report cannot be saved over it. The report is a check, not a fix, and the decision about the job stays with you and your printer.

How it is built

Built to read the file and leave it alone.

Read-only by design

The PDF is opened read-only through the Windows file picker and never written. Reports are new files, and saving over the file being checked is refused.

Nothing leaves your PC

ProofSlip runs in a Windows app container with no network capability. There is no account and no telemetry. One-time purchase in the Microsoft Store.

A check, not a fix

It reports what the file contains and declares. It does not embed fonts, convert color, resample images or flatten, and it does not validate PDF/X.

Head-to-head

How ProofSlip compares

Feature ProofSlip Online checker Full PDF editor subscription Checking by hand
Where the file is read On this PC. Nothing uploads. On the service's server, after you upload it On this PC On this PC
Fonts, boxes, color and image ppi All four in one pass, with image ppi measured per placement Varies by service; several cover all four Yes, among many more checks Fonts in a reader's properties; the rest is slow or hidden
Changes the file No. It reports and never writes to the PDF. Some offer a corrected copy Optional fix-ups —
Report to send back A one-page PDF report and an HTML report Varies; some ask for an email address first ✓ —
How you pay One-time purchase in the Microsoft Store Often no charge; some cap file size or checks per day Monthly or yearly subscription Your time on every file

FAQ

Straight answers—no glossary dump

What is a PDF preflight check?

Preflight means checking a print file for problems before it goes to press, especially the ones that are hard to see on screen: fonts that are not embedded, images too coarse for their printed size, color spaces the printer does not want, and page or bleed sizes that do not match the job. Printers check incoming files, and designers check before they send, so problems come back as a clear list instead of a reprint.

Which findings fail a file, and which only warn?

A file fails when a font that paints visible text is not embedded, when a color or grayscale image is below 150 ppi, when a 1-bit image is below 300 ppi, or when content on a page cannot be read. Images from 150 to 299 ppi, 1-bit images from 300 to 599 ppi, RGB or Lab color, mixed page sizes, a trim box without a bleed box, and bleed under 3 mm are warnings. Spot colors and a missing output intent are notes.

Does a PASS mean the file will print as intended?

No. A PASS means ProofSlip found no failing finding: every font that draws text is embedded, no image is below the fail limits, and every page could be read. RGB color and thin or missing bleed are warnings, so read them too. ProofSlip does not render pages, so it cannot see artwork that stops short of the bleed, text too close to the trim, overprint, transparency or ink build-up, and it does not validate PDF/X conformance. Your printer's spec sheet has the final word.

Can I change the limits, for example to require 300 ppi?

Not in this version. ProofSlip uses fixed limits: color and grayscale images fail below 150 ppi and warn below 300, 1-bit images fail below 300 and warn below 600, and bleed under 3 mm is a warning. Compare them with your printer's or your shop's spec sheet. Where the spec is stricter, treat the matching WARN rows as failures for that job; the effective ppi of every image is listed, so the comparison takes a glance.

Will ProofSlip change my PDF?

No. The PDF is opened read-only and is never written. ProofSlip is a check, not a fix: it does not embed fonts, convert color, resample images, add bleed or flatten anything. Each report is saved as a new file with a suggested name such as brochure-proofslip.pdf. If you pick the PDF being checked as the destination, ProofSlip refuses with a message that it is the file being checked, so the original cannot be overwritten by mistake.

Does anything leave my PC, and how do I get ProofSlip?

Nothing uploads. ProofSlip has no account and no telemetry, and it runs in a Windows app container that declares no network capability. It reads only the PDF you pick in the Windows Open dialog and writes only the report you save. It runs on Windows 10 version 2004 or later and on Windows 11, on x64 and ARM64 PCs. ProofSlip is a one-time purchase in the Microsoft Store, and the Store gives you a 15-day free trial of the full app, so you can check your own files before you buy.

Related pages

Every font in the PDF, and whether it is embedded. The resolution that matters is the one on the page. Trim, bleed and page size, read from the file itself. RGB, CMYK or spot? See what each page uses.

The PDF looks fine on screen.
Check it before the press does.

ProofSlip reads a client PDF on your PC and reports embedded fonts, page size, trim and bleed boxes, color spaces and effective image resolution, with one PASS or FAIL and a report you can send. It is a check, not a fix, and nothing uploads.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Open full product page

Technical specifications

Technical specifications for procurement

Spec Implementation
Data Sovereignty Reads only the PDF you pick in the Windows Open dialog, read-only; writes only the report you save as a new file; the Recent list (up to 20 files) and window size stay in the app’s own settings on this PC
Telemetry Status None; no account, no analytics, and no crash upload (a local error log keeps error types only, never file names or contents)
Core Runtime .NET 10 and WinUI 3 (Windows App SDK), packaged as MSIX; runs in an AppContainer that declares no capabilities
Network Requirements Fully functional offline; no network capability is declared, and the app makes no network connections
Deployment Compatibility Windows 10 version 2004 or later and Windows 11, x64 and ARM64; one-time purchase on the Microsoft Store with a 15-day free trial
Checks Embedded fonts, page size and named size, trim and bleed boxes with bleed per side, color spaces with spot names and output intent, and effective image resolution per placement
Verdict FAIL for a used font that is not embedded, color or grayscale images under 150 ppi, 1-bit images under 300 ppi, or unreadable content; WARN and INFO for the rest; limits are fixed in this version
Reports One-page PDF report (Letter or A4, matched to the file) and a self-contained HTML report with the full lists, both saved as new files
Originals Opened read-only and never written; saving a report over the file being checked is refused
Input One PDF at a time; files that need a password to open are refused, and files with only an owner password open read-only
Not included No fixing, color conversion or flattening; no page preview, batch checking or PDF/X validation