Drawing Sheet Sequence Checker
Find gaps, duplicates and out-of-order sheets in a numbering series, without assuming any particular numbering scheme.
Tool workspace
Nothing is uploaded. A dropped PDF is read in this tab; any other dropped file contributes only its name and is never opened.
Find gaps in a sheet numbering series
How do I find missing drawing sheet numbers?
Paste your sheet numbers, one per line or separated by commas, semicolons or tabs, drop drawing files to use their file names, or drop up to 20 PDFs to use the sheet labels they declare. A one-page PDF without a sheet label contributes its file name instead.
Choose which run of digits carries the sheet number, since a number like A-100-07 has two and only the project knows which counts.
Read the findings. Missing sheets are listed by the number they would have, formatted the way the rest of the series is.
How does the sheet sequence checker find gaps?
A sheet sequence checker finds the gaps, duplicates and out-of-order sheets in a numbered drawing set. Paste a list of sheet numbers, drop the drawing files to use their names, or drop PDFs to read the sheet labels they carry (or, for a one-page drawing without one, its file name). Nothing about your numbering scheme is assumed.
There is no standard for sheet numbering, so nothing here is hard-coded. Each identifier is split around its significant run of digits, and identifiers sharing the text around that run are compared with one another. A-101, A-102 and A-104 form a series with a gap at 103. A-101 and S-101 form two series of one each, and neither is missing anything, because those are different disciplines. The check that catches the most real errors is the one on zero padding: a set containing A-101, A-102 and A-0104 looks like one complete series and a single stray sheet, when it is really one series missing A-103, because the padding differs, and that is exactly how a missing sheet reaches site unnoticed. The tool reports the inconsistency rather than quietly merging the two, and offers merging as a choice you make knowingly. Once a set checks out complete, it can be reviewed in Xenmark.
How Xenmark makes it easy to check drawing sheet numbers for gaps
Missing sheets named, not just counted
A gap is reported by the sheet number that should fill it, formatted like its neighbours, so A-101, A-102 and A-104 point straight to A-103.
Nothing leaves your machine
Nothing is uploaded. Files are read in this tab and processed in memory, with no account and no server for them to go to.
Repeats and out-of-order sheets flagged
A sheet number that appears twice is reported, usually two revisions of one sheet, as is any series whose sheets are not listed in ascending order.
Sheet numbers read from PDF page labels
Drop a PDF and the sheet labels its producer recorded are added to the list, with a note of how many pages carried one. Plain page numbers are ignored, and a one-page drawing without a label adds its file name.
You decide which digits count
Choose whether the first or last run of digits is the sheet number, and whether letter case or zero padding splits a series. The result updates as you change them.
Nothing to install
It runs in the browser you already have. There is no plug-in, no desktop application and no sign-up to get through first.
Limitations
What this tool does not do, stated up front.
It compares the numbers you give it. It cannot know that a sheet was never drawn, only that nothing in your list occupies that number. Pasting a plain list of page numbers such as 1, 2, 3 will always look complete, because nothing marks them as page positions rather than sheet numbers; a PDF's own page labels that are only its page position are recognised and left out automatically.
An entry with no digits at all belongs to no series and is listed separately rather than guessed at.
A series spanning more than five hundred numbers is not checked for gaps; the tool says so and does not report the set as complete, because numbering that sparse almost always means the series is really several.
Questions
My numbers are like A-100-07. Which part does it use?
Whichever you tell it. The default reads the last run of digits, which suits discipline-series-sheet numbering. You can switch it to the first run instead, and choose whether case and zero padding split a series too. Nothing is guessed, because the answer differs between projects.
Why is it complaining about zero padding?
Because mixed padding hides gaps. If your set contains A-101, A-102 and A-0104, the tool would otherwise see a complete A-### series and a separate A-#### sheet, and never report that A-103 is missing. You can switch the check off once you know that is what is happening.
Do I have to upload the drawings?
No, and you cannot. Nothing leaves your browser. Dropped drawing files contribute only their names and are not opened. A dropped PDF’s structure is read, in this tab only, to find the page labels its producer recorded; its pages are not rendered and their drawings and text are not read.
Why did Xenmark build a free sheet sequence checker?
Xenmark AS is a Norwegian software company building browser-based drawing review tools for owners, consultants, operators and other teams that receive and review technical drawings. Those teams handle PDFs every day, and not every file should be sent to a website just to merge, split or check it — a tender document, a client’s drawing set, a revision that is not released yet. So these everyday tools are free and run entirely in your browser: no account, no upload step, and no server ever receives the file. You can check that yourself — open your browser’s network tab, read the page labels from a PDF set, and watch nothing leave. What this tool cannot do is listed under Limitations above.
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Reviewing the drawings, not just handling the files?
Xenmark is affordable PDF markup and structured drawing review in the browser. Invite reviewers, pin numbered comments on the sheet, track every one by author and status, and export a clean PDF and Excel when the review is done. Unlike these tools, a review is shared, so its drawings are uploaded to your Xenmark project.
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