The MCA21 portal rejected your PDF — now what

That is the search query behind "pdf to pdf/a online." A company secretary has spent the morning preparing an annual return. The document looks fine in Adobe Reader. The MCA21 upload screen rejects it with "file not in PDF/A format." The deadline is today. The CS pastes the rejection message into a search bar and clicks the first "PDF to PDF/A converter" that ranks.

Most of those tools upload the file to a server, run Ghostscript or a commercial library on a Linux box, and email back a result. Some produce valid PDF/A-1b output. Many produce files that pass the upload but fail when the regulator's validator runs the next business day — at which point the deadline has passed. A second category of tools, including most browser-based ones, calls itself a PDF/A converter while doing little more than setting a PDF/A flag in the metadata. The output renders fine; veraPDF rejects it; the regulator rejects it.

We built this as a checker rather than a converter because the honest path is to tell you exactly what would fail before you waste another upload attempt. The page below explains what we check, what we do not check, and which real tools (free and paid) actually produce valid PDF/A-1b output today.

Why this is a checker, not a converter

A real PDF/A-1b converter has to do four things that pdf-lib (the JavaScript PDF library that runs in the browser) cannot do well:

The browser-based competitors that claim to convert to PDF/A typically skip all four problems and just set a metadata flag. The output renders, the marketing copy is happy, and the file fails veraPDF. We are not interested in shipping that.

Tools that actually produce valid PDF/A-1b

If the pre-check shows FAIL on your file, here are the three tools that produce veraPDF-clean output today. None of them is browser-only.

Adobe Acrobat Pro

File → Save As Other → PDF/A. Acrobat Pro is the most reliable conversion path because the same vendor wrote the spec and the reference implementation. Subscription is around $14.99/month at the time of writing.

Ghostscript (free, open source)

One command, runs locally, no upload:

gs -dPDFA=1 -dPDFACompatibilityPolicy=1 \
   -sColorConversionStrategy=RGB \
   -sOutputICCProfile=sRGB.icc \
   -sDEVICE=pdfwrite \
   -o output.pdf input.pdf

sRGB.icc ships with most Ghostscript installs (look in the iccprofiles/ directory). On macOS: brew install ghostscript. On Ubuntu: apt install ghostscript. On Windows: ghostscript.com/releases.

LibreOffice (free, open source)

File → Export As → Export As PDF → General tab → check "PDF/A-1a". Works only when the source document is editable in LibreOffice (.docx, .odt, .xlsx, etc.). The output is generally clean but has occasional font-embedding gaps for less common scripts — run our pre-check on the result.

India regulatory context — when PDF/A actually matters

Three regulatory contexts in India routinely demand PDF/A-conformant output:

Ministry of Corporate Affairs (MCA21). The MCA21 portal accepts annual returns, board resolutions, and director KYC submissions. Several form types require PDF/A and the upload screen rejects non-conformant files with a generic error. The MCA general circulars on e-filing reference ISO 19005 directly. A failed upload near a deadline is the most common reason a CS searches for "pdf to pdf/a converter" — and the reason we built the checker first.

GST Network (gst.gov.in). Taxpayer document submissions for refund claims, advance ruling applications, and notice replies sometimes require PDF/A archival format. The portal validation is less strict than MCA21 but still rejects files with embedded multimedia or encryption.

High Court e-filing portals. The e-Courts project (ecourts.gov.in) and several High Court e-filing portals (Delhi HC, Bombay HC, Karnataka HC) accept case documents in PDF/A. The validation rules vary by court — the Delhi HC e-filing rules document explicitly references PDF/A-1b. For a missed-deadline case, a non-conformant PDF rejection is the reason a litigant pays a printer to certify a paper copy at 11 PM.

For all three contexts, the cost of a failed validation is concrete — a missed deadline, a paid extension, a paper-print fallback. That is why we will not ship a fake converter. The pre-check tells you the truth in 5 to 15 seconds, in your browser, without ever uploading the file.

Privacy — why browser-local matters here

PDFs that get pre-checked are disproportionately sensitive — annual returns, board minutes, court submissions, GST refund claims. The cost of routing them through a third-party server is asymmetric: most files would never matter, but the ones that do are exactly the ones a server log retains.

This tool runs entirely in your browser. The PDF bytes are read into the page's memory, scanned by JavaScript, and the report is rendered locally. There is no upload. Open dev tools, switch to the Network tab, drop a file, and run the checks — you will see zero PDF requests. The privacy claim is verifiable, not just stated.

If you are routing a sensitive submission through us, that should be a verifiable promise. We'd rather you check than trust.

Frequently asked questions