# Fastify vs Express: source lines of code compared

As of 2026-09-07, fastify/fastify contains 14,744 total lines (10,989 code) across 80 files, while expressjs/express contains 9,400 total lines (2,617 code) across 70 files as of 2026-09-10. fastify/fastify is about 4.2x the size of expressjs/express by code lines. Code size is not code quality: a larger count only means more source material, not a better or worse project.

| Metric | [fastify/fastify](https://octocounts.com/github/fastify/fastify) | [expressjs/express](https://octocounts.com/github/expressjs/express) |
| --- | ---: | ---: |
| Files | 80 | 70 |
| Total lines | 14,744 | 9,400 |
| Code lines | 10,989 | 2,617 |
| Comment lines | 2,183 | 5,223 |
| Blank lines | 1,572 | 1,560 |
| Languages counted | 5 | 7 |

Top languages in fastify/fastify: JavaScript (74.6% of code), TypeScript (23.2% of code), JSON (2.0% of code). Top languages in expressjs/express: JavaScript (90.4% of code), JSON (3.8% of code), Handlebars (2.7% of code). JavaScript, JSON appear in both top language lists; TypeScript, Shell, Markdown appear only in fastify/fastify's top languages; Handlebars, CSS, HTML appear only in expressjs/express's top languages.

Methodology: both counts come from cached OctoCounts reports generated with tokei. fastify/fastify was counted at ref main (commit ac28821df11d) on 2026-09-07; expressjs/express was counted at ref master (commit bed501c695a6) on 2026-09-10. See the [counting methodology](https://octocounts.com/docs/methodology) for ignored directories and analysis options.
Evidence and next steps:

- [fastify/fastify SLOC report](https://octocounts.com/github/fastify/fastify)
- [expressjs/express SLOC report](https://octocounts.com/github/expressjs/express)
- [Compare fastify/fastify and expressjs/express interactively](https://octocounts.com/compare?left=https%3A%2F%2Fgithub.com%2Ffastify%2Ffastify&right=https%3A%2F%2Fgithub.com%2Fexpressjs%2Fexpress)

Note: code size is not code quality. OctoCounts only reports reproducible line counts and makes no claim that either project is better.

## Compare FAQ

### Which has more lines of code, fastify/fastify or expressjs/express?

fastify/fastify has more code: 10,989 code lines versus 2,617 for expressjs/express, about 4.2x as much, based on cached OctoCounts reports as of 2026-09-10.

### Does more source lines of code mean more complexity?

Not necessarily. SLOC measures size, not complexity, quality, or maintainability. A larger codebase can mean more features, more generated or vendored code, more verbose language idioms, or more tests — none of which imply the code is harder to work with. Use SLOC to gauge the scale of what you'd be reading or maintaining, not as a quality signal for fastify/fastify, expressjs/express, or any repository.

### How is this comparison calculated?

Methodology: both counts come from cached OctoCounts reports generated with tokei. fastify/fastify was counted at ref main (commit ac28821df11d) on 2026-09-07; expressjs/express was counted at ref master (commit bed501c695a6) on 2026-09-10. See the counting methodology for ignored directories and analysis options.

### Can I compare a different branch, tag, or commit?

Yes. This page shows the default branch for each repository. Use the interactive comparison tool to pick any public GitHub repository, branch, tag, or commit SHA for both sides and get a fresh side-by-side report.

## Related OctoCounts pages

- [Interactive repository comparison](https://octocounts.com/compare)
- [Recently analyzed repositories](https://octocounts.com/recent)
- [Popular SLOC reports](https://octocounts.com/popular)
- [Trending GitHub repositories](https://octocounts.com/trending)
- [Hall of Monoliths](https://octocounts.com/hall-of-monoliths)
- [GitHub SLOC counter guide](https://octocounts.com/docs/github-sloc-counter)
- [Counting methodology](https://octocounts.com/docs/methodology)
- [OctoCounts API docs](https://octocounts.com/docs/api)