Find out whether a PDF's underlying cross-reference table and object structure are actually intact — not just whether it happens to open, since most viewers silently repair minor structural damage without ever telling you. This goes beyond PDF Information's content summary by checking the file's structural soundness instead. See our guide: How to Tell If a PDF Is Structurally Valid.
or use the button below to add files
Drag & drop a file here
or use the button below to choose a file
File selected
Accepts PDF · up to 20 MB each
Processing your file…
This usually only takes a moment.
- PDF version
- Pages
- Encrypted
- Linearized (fast web view)
Errors
Warnings
Your file is processed on our server and deleted automatically afterward — see the privacy note below.
Overview
About PDF Structure & Validity Checker
Upload a PDF and this tool checks its internal cross-reference table and object structure for damage — a fundamentally different check from this site's PDF Information tool, which reports what a file contains (pages, size, metadata) rather than whether its structure is actually sound. Most PDF viewers, including the engine behind this site's own PDF tools, silently repair many structural problems (a broken cross-reference table, a wrong startxref offset) and render the file normally with no visible warning — so a document can open fine everywhere and still be carrying real damage that only shows up later, in a stricter consumer or an archival system. This tool surfaces that distinction instead of silently working around it, and also reports whether the file is encrypted and whether it is linearized ("fast web view").
Compatibility
Supported Formats
Accepts PDF (.pdf) input up to 20 MB. Reports a pass/warning/error verdict plus encryption and linearization ("fast web view") status — no output file is produced.
Guide
How to Use PDF Structure & Validity Checker
- Choose or drag in a PDF file.
- Click "Check PDF Structure".
- Review the pass/warning/error verdict and any specific issues it found.
Highlights
Features
- Structural soundness, not content Checks the file's cross-reference table and object structure for real damage — a different question than what PDF Information's content summary answers.
- Surfaces silently-repaired damage Reports structural problems most viewers work around without any visible warning, so damage does not go unnoticed until it hits a stricter system later.
- Encryption + fast web view status Also reports whether the file is encrypted and whether it is linearized for fast web viewing, in the same check.
- No files retained This is a report-only tool — no output file is created, and your uploaded PDF is deleted automatically after the check runs.
Applications
Use Cases
- Check a PDF generated by an unfamiliar or third-party tool for structural problems before archiving it long-term
- Diagnose why a PDF that opens fine in a browser fails in a stricter downstream system (a print workflow, a document-management platform)
- Confirm a file isn't encrypted or has the security settings you expect before sending it onward
Good to Know
Limitations
This is a diagnostic tool only — it reports structural problems but does not repair them; regenerating the file from its original source is usually the more reliable fix. A pass here means the core cross-reference/object structure is sound, not that every viewer will render the content identically.
Files are processed on our servers and are not shared with third parties. Files are deleted as soon as processing or download finishes. Any leftover temporary file is removed automatically by our cleanup process within the configured retention period (60 minutes). See our Privacy Policy for full details.
Support
Frequently Asked Questions
How is this different from PDF Information?
PDF Information reports what a file contains — page count, size, metadata. This tool instead checks whether the file's internal cross-reference table and object structure are actually sound, a completely different, structural question. A file can pass every PDF Information check and still have real structural damage that only this tool surfaces.
My PDF opens fine everywhere — why would it fail this check?
Most PDF viewers (including the engine behind this site's own tools) are deliberately lenient: they silently reconstruct a broken cross-reference table or work around a bad object reference and render the file normally, with no visible warning to you. That tolerance is exactly why this kind of damage usually goes unnoticed until a stricter downstream tool — a different viewer, a print workflow, an archival system — encounters the same file and does not recover as gracefully.
What does "linearized" mean?
A linearized PDF (also called "fast web view") is organized so a viewer can start displaying the first page before the whole file has finished downloading — useful for large PDFs viewed over the web. This is a structural property this tool reports, separate from whether the file has any actual damage.
Can this tool fix or repair a damaged PDF?
No — this is a diagnostic tool only. It reports what is wrong so you can decide whether to regenerate the file from its original source (usually the most reliable fix) rather than attempting an automated repair.
Is my PDF kept on your server?
No. This is a report-only tool — no output file is created, and your uploaded PDF is deleted automatically shortly after the check runs.
Keep Going
Related Tools
- Compress PDF Shrink a PDF by recompressing the images inside it as JPEG. You always get a file no larger than the original.
- PDF Information Read a PDF's page count, version, encryption flag and file size. The file is uploaded briefly and nothing is kept.
- PDF Duplicate Page Finder Find pages that are duplicated inside a single PDF — free and instant.
- PDF Font Checker List the fonts in a PDF: type, embedded or not, subset, encoding, and the pages that use them. Warns about fonts that are missing from the file. Export a report. In your browser.
- PDF Active Content Scanner Check a PDF for JavaScript, OpenAction, launch and submit actions, embedded files, XFA and automatic triggers, with plain-language explanations. A structural inspection, not an antivirus. In your browser.
- PDF Form Appearance Checker Find out why a filled PDF form looks blank: checks every field for a missing or empty appearance stream, hidden flags and a stored value that differs from what is drawn. In your browser.
- PDF Form Printability Checker Check whether the interactive fields of a PDF form will be included when it is printed: Print and Hidden flags, appearance streams, page boundary and layers, page by page. In your browser.
- Document Upload Preflight Checker Enter the requirements of an upload portal (size, formats, pages, paper, password, text layer, resolution, metadata) and check your file against them: PASS, WARNING or FAIL for each. In your browser.