Firmex Alternative
Firmex suits a team sharing chart-heavy workbooks that need to look right in a browser. Sifrsys suits a team whose workbooks carry Arabic text, Hijri dates, and numbers a buyer will check against a source cell. Both claims below are testable, and the Firmex ones cite Firmex.
The spreadsheet question
Firmex bet on coverage. Its published viewer renders data, charts, and images, opens Excel files up to 50GB, moves between worksheet tabs, and lets a viewer inspect formulas unless the uploader hid them as a file protection. That is a wide surface and it works.
Sifrsys bet on accuracy and on citation. It renders a narrower set of things and proves how closely it renders them. The test suite compares output against LibreOffice ground truth in real Chromium across four producer dialects, and a committed baseline fails the build if a number moves.
The fills row is why the rest is worth believing. A benchmark that reports 100% on everything has usually stopped measuring. Fills scored 99.7% on the 4 August 2026 run, 877 of 880 cells, against a committed 99.3% floor where a regression breaks the build.
Umm al-Qura Hijri dates and Arabic-Indic digits render correctly in Sifrsys where LibreOffice, the ssf library, and every competitor put through that suite render them wrong. The specific failure is worth naming: the [$-2060401] number format used to render a US dollar sign against Arabic-Indic digits. That is fixed. If your workbooks come out of a Gulf finance team, this is the row that decides the evaluation, and it is not a row most vendors have ever been asked about.
Sifrsys vs Firmex
Firmex rows read from firmex.com on 4 August 2026. Where their documentation is silent, the row says so.
| Criterion | Firmex | Sifrsys |
|---|---|---|
| Charts in the Excel viewer | Rendered, with images | Not yet |
| Formula inspection | Yes, unless the uploader hid them | Values, not formula editing |
| Spreadsheet file ceiling | 50GB, larger files download | 5M cells, then a raster fallback |
| Measured render fidelity | Not published | 100% on five dimensions, 99.7% fills against a 99.3% floor |
| Hijri and Arabic-Indic digits | Not addressed in the docs checked | Umm al-Qura, verified in tests/fidelity/ |
| AI answers with cell citations | Not published | Revenue!B14:F34, clickable |
| Watermarking | Tiled in the viewer and on downloads | Burned into the page bitmap |
| Pricing model | One-time per project, or annual subscription | Flat monthly plan |
| Published prices | None. Quote form | $0 / $399 / $999 / custom |
| Ownership | Datasite business unit since July 2021 | Independent |
The honest part
Pricing model
Firmex publishes its pricing structure without publishing prices. The Single Project Data Room is a one-time fee, priced on data requirements and project length, with access for a fixed time frame. The subscription is an annual fee, priced on data volume over the year, covering unlimited projects. Both end at a quote form.
The structure is clear and the number is not, which makes budgeting a negotiation. Sifrsys puts the numbers on the pricing page: free Starter, Teams at $399 per month, Pro at $999 per month, custom Enterprise, no per-page fees, and a 14-day trial that takes no credit card. If a published number is the thing you care about most, SecureDocs publishes one too and it is lower than ours. That comparison says so.
Switching
If you hold a single-project room, wait for it to close and start the next one elsewhere. If you hold a subscription, the switch is an export of the folder tree and originals, an upload, and a rebuild of the permission map. Files are parsed and indexed on arrival, and participants join by magic link with no account to create. Test your heaviest workbook first, before anything else, because the chart gap above is the one thing that will not survive the move. For the first ten paying companies Sifrsys does the migration and permission mapping at no charge. The same pattern applies moving from Intralinks.
Sources
Read from the vendor's own pricing page or documentation on the date shown. Vendors change these pages. Check the date before you rely on a row.
Firmex alternative FAQ
Run the test yourself
Take the file with merged headers, Arabic labels, and a Hijri date column, and load it into each. The free plan takes no card, so the test costs an afternoon. The Trust Center lists what Sifrsys does not claim, charts included.
Free to start · No per-page fees · No credit card required