Top 11 JavaScript Functional Projects

fantasy-land

1 22 10,208 0.8 JavaScript

Specification for interoperability of common algebraic structures in JavaScript

Project mention: JavaScript's Missed Opportunity: Async/Await, Optional Chaining, and flatMap are the same thing | dev.to | 2025-02-19

(This was one of the purposes of the Fantasy Land specification, to define common interfaces for generalized operations that could benefit from language-syntax-support.)
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folktale

2 1 2,043 0.0 JavaScript

[not actively maintained!] A standard library for functional programming in JavaScript
Rambda

3 2 1,737 8.7 JavaScript

Typescript focused FP library similar to Remeda and Ramda
partial.lenses

4 3 921 0.0 JavaScript

Partial lenses is a comprehensive, high-performance optics library for JavaScript

Project mention: Show HN: JAQT – JavaScript Queries and Transformations | news.ycombinator.com | 2024-09-16

For the same purpouse I ofter use this https://github.com/calmm-js/partial.lenses
pampy.js

5 2 552 2.4 JavaScript

Pampy.js: Pattern Matching for JavaScript
puresql

6 1 51 0.0 JavaScript

ES6/7 ready SQL library for node.js inspired by Clojure's yesql
eth-fun

7 3 28 4.7 JavaScript

A functional and state-less library for the Ethereum JSON-RPC.
InfluxDB

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kesh

8 11 22 5.7 JavaScript

A simple little programming language that could one day compile to JavaScript
declarative-merge

9 1 6 8.7 JavaScript

Merge objects/arrays declaratively
openinf-util-text

10 2 4 0.0 JavaScript

Cross-platform terminal-friendly text utilities
noLoopFor

11 1 3 0.0 JavaScript

JavaScript library for making functional loops

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).

JavaScript Functional discussion

JavaScript Functional related posts

JavaScript's Missed Opportunity: Async/Await, Optional Chaining, and flatMap are the same thing

1 project | dev.to | 19 Feb 2025
Have any of you designed a conlang, and then designed a programming language based on the conlang or any fictional culture that would use it?

2 projects | /r/ProgrammingLanguages | 30 Mar 2023
Too many words about Rust's function syntax

1 project | /r/ProgrammingLanguages | 28 Jan 2023
Ask HN: Tools you have built for yourself?

17 projects | news.ycombinator.com | 23 Jan 2023
How elaborate could/should a transducers combiner function be?

2 projects | /r/functionalprogramming | 5 Jan 2023
General Functional Programming Resources

3 projects | /r/functionalprogramming | 17 Dec 2022
Updates from the 93rd TC39 meeting

2 projects | /r/javascript | 3 Dec 2022
A note from our sponsor - SaaSHub
www.saashub.com | 1 Sep 2025

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Index

What are some of the best open-source Functional projects in JavaScript? This list will help you:

#	Project	Stars
1	fantasy-land	10,208
2	folktale	2,043
3	Rambda	1,737
4	partial.lenses	921
5	pampy.js	552
6	puresql	51
7	eth-fun	28
8	kesh	22
9	declarative-merge	6
10	openinf-util-text	4
11	noLoopFor	3