Iteration Layer
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Sheet Generation

Iteration Layer vs OpenPyXL

OpenPyXL is the standard Python spreadsheet library — essential if your stack is Python, a dependency if it isn't.

Why developers switch from OpenPyXL

openpyxl means writing cell-by-cell Python code and hosting the service yourself.

Any language, not just Python

OpenPyXL is Python-only. If your backend is Go, Node.js, Elixir, or Java, generating Excel files requires a Python subprocess or sidecar. Our API accepts JSON from any language with HTTP support.

No Python environment to manage

OpenPyXL requires a Python environment with the correct package versions. In production, that means managing a virtualenv or Docker image for spreadsheet generation. We are a managed API: one endpoint, one request.

Declarative JSON, not cell-by-cell iteration

OpenPyXL requires building workbooks row by row: create workbook, create worksheet, iterate rows, set cell values, apply styles. Our JSON payload describes the entire sheet structure declaratively.

Feature-by-feature comparison

We went through the docs so you don't have to. Here's how every feature compares — including the ones where we're not the better choice.

Feature Iteration Layer OpenPyXL
Formula support
Yes

Generate spreadsheets with Excel-compatible formulas

Yes

Full formula support through programmatic API calls

Multi-sheet support
Yes

Generate workbooks with multiple named sheets

Yes

Full multi-sheet workbook support with programmatic API

Output formats
3 formats

XLSX, CSV, and Markdown output

1 format

XLSX output only

Sheet definition style
Declarative JSON

Entire spreadsheet described declaratively in a single JSON payload

Imperative API

Spreadsheets built row by row with imperative cell-by-cell iteration

Open source
Proprietary

Closed-source managed SaaS platform

MIT license

Free and open source under the MIT license

Data science ecosystem
HTTP API

Standard HTTP API without native data science library integration

Native

Native integration with pandas and NumPy for data science workflows

Read & modify Excel
Generation only

Generates new spreadsheets from JSON — does not read or modify existing files

Read + write

Can read, modify, and write back existing Excel files

EU hosting
EU only

All processing happens exclusively on EU-hosted servers

Your choice

Runs on your infrastructure, so data residency depends on where you deploy

Pricing
$0.033

1 credit per action

Compute only

Self-hosted OSS

Infrastructure required
None

Fully managed API with no Python environment, virtualenvs, or Docker images to manage

Self-hosted

Requires managing a Python environment with the correct package versions in production

GDPR / Data privacy
Zero retention

No files or results stored beyond temporary 90-day logs

Your responsibility

Data privacy depends entirely on your deployment and infrastructure choices

Pricing

Start usage-based. Switch to a subscription when your volume becomes predictable.

Pay as you go

Usage-based

$0.033 to $0.022 / credit

Graduated pricing. Your effective rate decreases automatically as monthly usage grows.

  • No monthly commitment
  • Pay only for credits used
  • Automatic volume discounts as usage grows
Subscriptions

Predictable volume

From $29.99 /month

Fixed recurring credit packs with lower effective credit prices for steady usage.

  • Lower effective per-credit prices
  • Fixed recurring credit packs
  • Predictable monthly budget
All APIs included Free trial credits per API Project-based budget caps Auto overage billing

Still evaluating?

See how we compare — and where the competition still wins. Choosing the right tool shouldn't require a week of research.

Start building in minutes

Free trial credits included.

Zero data retention Made & hosted in the EU $65 free trial credits