FAQ
Everything below is answered in more depth somewhere else on this site; each answer says where. Nothing here is a new promise.
The product
Section titled “The product”What does Rendlio actually convert?
Section titled “What does Rendlio actually convert?”.xlsx and .xlsm workbooks to PDF, PDF/A-2b (archival PDF), or PNG — one image per page. Every conversion also emits a machine-readable compatibility report naming every deviation from faithful rendering, with locations.
Do I need Excel, Office, or LibreOffice on the host?
Section titled “Do I need Excel, Office, or LibreOffice on the host?”No. Rendlio is a single self-contained binary. No Office, no LibreOffice, no service accounts, no headless browser. See Install.
Does it need network access?
Section titled “Does it need network access?”Never, for any purpose. The engine opens no network connection at all — no activation, no telemetry, no font downloads, no phone-home. Licences verify offline by signature against public keys embedded in the binary, which is why an air-gapped host works exactly like a connected one. This is enforced in the codebase by a static analyzer that bans the underlying APIs, not by policy — see the security model.
Does it recalculate formulas?
Section titled “Does it recalculate formulas?”By default, no: cached formula values from the workbook are rendered as-is (--recalculate off). Strict recalculation (--recalculate=strict-v1) is planned; requesting it in a build that does not have it is a usage error rather than a silent no-op. The report tells you how many formula cells had no cached value to render. See the CLI reference.
Is the output reproducible?
Section titled “Is the output reproducible?”Yes, deliberately. Add --deterministic and pin --reference-date, and identical input plus identical options produce identical bytes — across platforms and across the four supported architectures. That property is also what makes the fidelity numbers re-runnable.
How do I know what it got wrong?
Section titled “How do I know what it got wrong?”That is the whole point of the report. Every run prints a one-screen summary to stderr and, with --report, writes the full JSON. unsupported, approximated, and skipped entries each carry a status, a count, locations, and a plain-language detail — and the process exit code is the report’s verdict as a number, so CI can gate on it without parsing anything. Recipes are on the compatibility report page.
Can I try it without installing anything?
Section titled “Can I try it without installing anything?”Yes — the playground converts a workbook in the browser with no account, using the shipping engine in watermark mode. Files and results are deleted within one hour, and diagnose-only privacy mode analyses structure without rendering cell contents at all.
Is there a published fidelity percentage?
Section titled “Is there a published fidelity percentage?”No, and there will not be one. Fidelity is evidenced feature by feature in the compatibility report and in per-area scores on the fidelity page; a single headline figure would depend entirely on which features you weighted. The reasoning, and the rules on what may be published at all, are on the fidelity methodology page.
Licensing and price
Section titled “Licensing and price”Do I need a licence to evaluate it?
Section titled “Do I need a licence to evaluate it?”No. Without a licence Rendlio converts with full features and identical fidelity — every output page just carries a diagonal evaluation watermark, and the run emits W9001 so watermarked conversions exit 1 at best and never 0. There is deliberately no feature-crippled tier. Want to evaluate watermark-free? Request a 30-day trial (business email required).
What does “per legal entity” actually mean?
Section titled “What does “per legal entity” actually mean?”One licence covers one legal entity — every developer, server, CI runner, and internal product inside it. There are no seat tiers, headcount bands, or per-server counts anywhere in the price list. Enterprise widens the unit to a corporate group: the parent and its named affiliates are covered by one licence, listed in the licence file itself. Full detail: Licensing guide.
Is there a free tier?
Section titled “Is there a free tier?”Yes — Community, free, for any entity under USD 1M annual revenue, self-certified, that is not offering conversion itself as a service to third parties. It is the same test as the source licence’s production grant, worded the same way, so you cannot satisfy one and fail the other. Note that even the free tier needs a minted licence file; minting is self-serve and takes a minute. Which tier am I?
What do “SaaS” and “OEM” included mean?
Section titled “What do “SaaS” and “OEM” included mean?”You may run Rendlio inside your own SaaS and ship it embedded (OEM) in your product, at no extra fee — the licence price is the whole price. One boundary: building a product whose main job is conversion itself (a third-party converter) requires the Enterprise licence, which carries that right explicitly. See pricing and the licensing guide.
What happens after my 12 months of updates run out?
Section titled “What happens after my 12 months of updates run out?”Nothing stops working. Your licence is perpetual: maintenance_until gates which builds it covers, not whether it works. Every build released on or before that date is covered forever; a newer build runs in evaluation mode until you renew. Renewal is a one-time purchase at 40% of the then-current list price, whenever you choose — reminders at T-60/30/7 by email, never an auto-charge. See the perpetual fallback.
Why can I not buy Professional or Enterprise today?
Section titled “Why can I not buy Professional or Enterprise today?”Because the engine is pre-launch, and we do not sell what has not shipped. Both go on sale at GA at exactly the prices published on the pricing page, locked from day one. The Founding licence is the way to buy in now, and it is credited toward Professional at GA.
What protects Founding buyers if the project never reaches GA?
Section titled “What protects Founding buyers if the project never reaches GA?”The founding offer terms carry a kill clause: if Rendlio is discontinued before GA, you choose a full refund — or you keep a perpetual, unsupported build plus committed delivery of the source code.
What is the refund policy?
Section titled “What is the refund policy?”30-day money-back, handled by Paddle — the policy. One honest consequence of the zero-phone-home architecture: we cannot reach into your machines to disable anything, so a refund marks the licence revoked in our records and the terms oblige you to stop using it.
Who is the seller?
Section titled “Who is the seller?”The Rendlio Association (Verein Rendlio), a Swiss non-profit. Paddle.com acts as merchant of record and handles payment, VAT, and invoicing — enter your VAT ID at checkout for reverse-charge invoicing. More on the association page.
Is the source code available?
Section titled “Is the source code available?”Yes — the engine’s source is published under the Business Source License 1.1. Anyone may read, copy, modify, redistribute, and make non-production use of it without any revenue condition, and each released version’s licence automatically becomes Apache 2.0 four years after its release. The fenced-off uses are hosted conversion services and redistribution to third-party developers. Plain-words summary: Licensing guide.
Running it
Section titled “Running it”How do I gate a CI pipeline on a conversion?
Section titled “How do I gate a CI pipeline on a conversion?”On the exit code, which is the report’s verdict: 0 clean, 1 rendered with warnings, 2 unsupported content, 3/4/5 failures. Most pipelines treat <= 1 as pass and 2 as review. Ready-made GitHub Actions and GitLab CI jobs, including the set +e handling Actions needs, are on the Deployment page.
Is it safe to point at files I do not trust?
Section titled “Is it safe to point at files I do not trust?”That is the design assumption. The engine treats every workbook as hostile: guarded container and XML parsing, decompression-bomb caps, a hard rejection of encrypted containers, macros never executed, images bounds-checked before decode, and a timeout and memory cap you set. For an upload path, add the RENDLIO_SANDBOX=1 hardening profile and a hard container limit. Full contract: security model.
Can a limit hit leave me a half-written PDF?
Section titled “Can a limit hit leave me a half-written PDF?”No. Documents are written to a temp name and atomically renamed only after the whole document is written; on any failure the temp files are deleted, the run exits 4, and the report is still written naming the limit that fired and its measured value. You never gate on a truncated document.
Can I share a report with support if the workbook is confidential?
Section titled “Can I share a report with support if the workbook is confidential?”Yes. Reports never contain cell contents — detail and message strings are static templates plus counts and locations, and a CI leak test enforces it. rendlio diagnose produces the same report without rendering or writing any document at all. See diagnose mode and privacy.
A font in my workbook is not installed. What happens?
Section titled “A font in my workbook is not installed. What happens?”Rendlio uses its bundled fonts by default — deterministic on every host — and records every substitution in the report as requested → used with a reason, plus a warning that layout may shift. Point it at your own corporate fonts with --fonts-dir or RENDLIO_FONTS_DIR, or add OS fonts with --use-system-fonts (off by default, for determinism). You can gate CI on fonts.substitutions being empty.
Which platforms are supported?
Section titled “Which platforms are supported?”win-x64, linux-x64, linux-arm64, and osx-arm64 as self-contained archives; a .NET global tool for hosts with the .NET 10 SDK; and one container image that runs on x64 and ARM64. Deterministic output is byte-identical across all of them. See Install.
How do I report a security issue?
Section titled “How do I report a security issue?”Email security@rendlio.com with the version, the platform, and a reproducing workbook if you have one. See reporting a vulnerability.
Still unanswered?
Section titled “Still unanswered?”Email hello@rendlio.com. If the question turns out to be a documentation gap rather than a one-off, it lands on this page.
Next steps
Section titled “Next steps”- Quickstart — first faithful PDF plus report, in five minutes
- Install — every channel, and how to verify a release
- Licensing guide — the tier table and the licence file
- Security model — hostile-file handling, end to end