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Sheet Generation

Iteration Layer vs ExcelJS

ExcelJS is the go-to Node.js spreadsheet library — great if you're already in Node, not if you're not.

Why developers switch from ExcelJS

ExcelJS means writing row-by-row Node.js code and hosting the service yourself.

Any language, not just Node.js

ExcelJS is a Node.js library. If your backend is Python, Go, Elixir, or anything else, generating Excel files means a sidecar Node.js process. Our API is language-agnostic — one HTTP call from any language.

No infrastructure to manage

Using ExcelJS in production means deploying Node.js, managing memory for large spreadsheet generation, handling concurrency, and monitoring the process. We handle all of that.

Declarative JSON, not cell-by-cell imperative code

ExcelJS requires building spreadsheets row by row, cell by cell: add row, set cell value, set cell style, repeat. Our content model describes the entire spreadsheet in a single JSON payload.

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 ExcelJS
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

2 formats

XLSX and CSV output supported

Sheet definition style
Declarative JSON

Entire spreadsheet described declaratively in a single JSON payload

Imperative API

Spreadsheets built row by row, cell by cell with imperative API calls

Open source
Proprietary

Closed-source managed SaaS platform

MIT license

Free and open source under the MIT license

Cell formatting
JSON styling

Cell styles defined through JSON properties in the content model

Rich formatting

Rich cell formatting including merged cells, conditional formatting, and data validation

Community
Growing

Actively growing platform with expanding documentation

Established

Large community with active maintenance and frequent releases

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 deployment, scaling, or memory management required

Self-hosted

Requires deploying and managing a Node.js process 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