PDF accessibility checker and remediation guide
Read this once before you process a document for real. It takes five minutes and explains what the result means and what it does not mean.
- 1. What it does / does not do
- 2. How to run a document
- 3. Reading a result
- 4. The review list
- 5. Tagged vs. untagged PDFs
- 6. Your files
- 7. Known limits of this release
- 8. Try it with known documents
- 9. Compare two versions
1. What PDFAccess does, and does not do
We find accessibility problems that can be detected automatically, repair what we can, and give you a copy to review. Your original stays unchanged. Follow the checklist before publishing; a person still needs to check how the document reads.
Technical scope and limitations
It does: take a PDF, run the independent validator veraPDF against PDF/UA-1, fix the machine-checkable defects that can be fixed without guessing (document language, title, PDF/UA metadata, link descriptions taken from the link's own destination or visible text, table header scope, list and heading sequence, content the export left outside the tag structure, decorative graphics marked as artifacts), validate again, and give you the remediated file, an evidence report and a list of what a person still has to check.
It does not: make a document accessible by itself. It never invents image descriptions, requires review of inferred heading levels, cannot repair fonts that were not embedded when the PDF was made, does not process scanned, encrypted or form PDFs, and does not check anything a machine cannot check: meaning, reading order, whether a table makes sense. A green "machine checks pass" is a necessary condition, not a statement that the document is accessible. The report says exactly that.
2. How to run a document
- Choose or drop a text-based PDF (up to 50 MB) on the start page and press Check my PDF free.
- Wait while we check the PDF, apply repairs and check the result. Larger documents may take a minute or more.
- Read the free result and exact price. If the supported result helps you, pay once through Stripe to unlock the review list (section 4), processed PDF and reports. A result without a reading structure is not sold.
- Delete your files when you are done, or let them expire after 24 h.
3. Reading a result
| Headline | Meaning | What you do |
|---|---|---|
| Automatic checks passed | veraPDF found no PDF/UA-1 machine-check failure in the output. | Work through the review list; those items are what machines cannot see. |
| Your review is needed | Automation did all it can. What remains needs a person: mostly image descriptions. | Write the descriptions in the review list, then re-validate. |
| The original document needs a fix | A technical defect of the original PDF that cannot be repaired from the PDF alone (typically fonts). | Re-export the document from the authoring tool with fonts embedded, then run it again. |
| Some automatic repairs did not work | PDFAccess should have fixed this and did not. | Send us the file if it is public; keep the original until we answer. |
| Some problems still need investigation | A failure whose cause we have not established. We show the rule and the evidence as they are. | Treat as unresolved. Do not publish on the strength of this result. |
| Not supported / stopped safely | Scanned, encrypted or broken input, or a refusal to hand over an altered file. | Nothing was changed; your original is untouched. |
The result shows whether automatic checks passed and how many problems they found before and after processing. The change is a difference in counts, not proof that every earlier problem was repaired. Document structure details and the full check results are available in the expandable technical sections. Zero detected problems does not guarantee accessibility.
The evidence report (JSON) contains the raw veraPDF results before and after, every remediation step with counts, the review list and the SHA-256 of your original. It is meant to be attached to an accessibility statement or handed to an auditor.
4. The review list
- Describe the image on page N — the one thing you can write straight into the PDF here. Say what the image tells the reader in this context, or mark it decorative if it carries no information. The file is re-validated after each save.
- Check the heading structure / Check tables / Check reading order — things only a person can confirm. Open the PDF in a tag viewer or with a screen reader, check, and press I have reviewed this. That records your check; it is not a machine result.
- Source document must be fixed — a dead end on purpose. Fix the source, re-export, run again.
- Unclassified — shown with the rule and evidence, claimed nothing about.
You can download the file while tasks are still open; the card warns you. For a document that will be published, settle the open items first.
5. Tagged vs. untagged PDFs
Tagged (Word, InDesign, Aspose, most case-management exports): the tag structure the author's tool produced is kept. PDFAccess applies supported technical repairs. The free check shows what changed in your particular document; historical SDK corpus results are not a success-rate claim for this native service.
Untagged (print drivers, some PDF generators, "Save as PDF" without tagging): basic tagging builds paragraphs, inferred headings, lists and figures. Review the inferred structure before publishing. It does not build table tags, describe images, or tag text inside Form XObjects and rotated pages. Missing structure needs repair in the source or a tag editor.
6. Your files
Your file is uploaded to the PDFAccess server over HTTPS and processed there; it does leave your computer. It is not sent to any other service: the validator and the engine run on that server, and there is no CDN or AI call. First-party funnel analytics records event names and pseudonymous identifiers, never PDF content, filenames or alt text. The uploaded original is stored read-only next to the output and is never modified (the report carries its SHA-256 so you can prove it). Files are deleted when you press Delete my files now and automatically after 24 h; finished jobs, ownership and payment state survive ordinary restarts only until their original deadline. Unfinished or malformed saved jobs are removed. Only you — the same signed browser session — can see, download or delete your jobs. A job ID alone grants no access. Who runs the server and where is stated on the privacy page. During Early Access, use your own documents or public test documents, not documents with other people's personal data.
7. Known limits of this release (early access v0.5.0-early-access)
- One document at a time, one worker: a long document blocks the next one.
- No permanent archive: the retention limit removes the result. Download the PDF and report before the deadline. An ordinary restart recovers finished jobs without extending retention.
- One document processed at a time and a short waiting queue; when the queue is full the upload is refused with a clear message and nothing is stored. Try again in a minute.
- Image descriptions and structural checks are the reviewer's work; the tool provides the list, the preview and the re-validation, nothing more.
- Table shape is repaired, table meaning is not judged. Fonts are not embedded.
- This build uses the open-source engine: no watermark; basic tagging requires human review.
- Rules veraPDF reports that we have not yet classified are shown as "unclassified", never relabelled as resolved.
8. Try it with known documents
Three public documents cover the three outcomes you will see. Download them from the
organisation's own site (links in the repository's fixtures/real/sources.txt)
or use any document of the same kind:
| Document | Kind | Expected |
|---|---|---|
| Kouvolan kaupunki, kaupunginhallituksen pöytäkirja 1/2026 (Aspose.Words export) | tagged minutes, tables | Automatic checks passed; review list: tables, reading order. |
| Helsingin Satama Oy, vuosikertomus 2025 (InDesign) | tagged report, links, figures with descriptions | Automatic checks passed after 44 orphan text lines were tagged; review: reading order on page 5. |
| Any "Save as PDF" print-driver file, e.g. Raahen kaupunki tilinpäätös 2024 | untagged | Left untagged, metadata fixed, clear notice. |
Developers can reproduce the same three cases from the command line; see
docs/PILOT_GUIDE.md in the repository.
9. Compare two versions
Upload the earlier PDF and wait for its result. Upload the updated PDF, then choose Compare versions. Select the earlier and updated files and start the comparison. It shows pages with text changes and changes in automatic check results.
Pages are compared by page number. Adding or moving a page can make later pages appear changed too. Pictures, layout and reading structure still need your review. Earlier review confirmations are not copied. Comparison does not delay automatic file deletion.