Fastmail vs TaxJar

Fastmail (Open-source software developed at Fastmail.) and TaxJar (Making sales tax filing easier for more than 20,000 online sellers and merchants across the world.) both appear on the Smoower Developer Ecosystem Index.

Fastmail (rank #430) holds a modest lead over TaxJar (rank #693) on the overall Smoower ecosystem score (40 vs 31). The gap of 9 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), TaxJar is clearly ahead of Fastmail. On education (docs, guides and learning material for developers), TaxJar is slightly ahead of Fastmail. On community (issue response, PR reviews and discussion health), Fastmail is ahead of TaxJar. On reach (how visible the ecosystem is beyond its own repos), Fastmail is clearly ahead of TaxJar. On momentum (release cadence and how fast the ecosystem moves), Fastmail is ahead of TaxJar.

Fastmail carries 6,316 GitHub stars across 38 public repos, with 12 repositories active in the last 90 days and 2 external contributors on record. TaxJar shows 490 stars across 39 public repos, 1 active in the last 90 days and 3 external contributors. The star gap on its own does not decide the comparison, but Fastmail's footprint is roughly 12.9x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

Fastmail is the stronger read for anyone weighting reach. TaxJar looks better where code quality is the deciding factor. The table below breaks the scores down pillar by pillar; the linked profiles cover the underlying repos, docs and community signals in full.