Parsing Gigabytes of JSON per Second · HackerPapers discussions

Parsing Gigabytes of JSON per Second — HN submission

Sun, 25 Oct 2026 22:47:18 GMT

Show HN: simdown – use SIMD to parse Markdown at ~1 GB/s

The SIMD path currently needs arm64 (NEON) and GOEXPERIMENT=simd. I've only benchmarked on an Apple M4, but it should help on any arm64 chip (Graviton, Ampere, etc.). Elsewhere it falls back to a scalar path that does ~300 MB/s, still ahead of cmark and goldmark. If you know of a faster CommonMark parser, please tell me and I'll add it to the benchmarks. Under the hood, it borrows a lot from this paper on using simd for json parsing: https://arxiv.org/abs/1902.08318

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by Rendello

Fri, 11 Sep 2026 16:24:56 GMT

I like burntsushi's string-searching work because it's well documented, split modularly into libraries/applications, and runs the gamut from low- to high-level (his blog posts and comments online are extremely helpful too). I use these three tools which he maintains: Low level: memchr [1]; Medium level: Regex (Rust crate) [2]; High level: ripgrep [3]. Other names to look out for are the previously aforementioned Wojciech Muła, as well as Daniel Lemire (of simdjson [4][5]). Not SIMD-specific, but Data-Oriented Design can be a big help in terms of thinking about SIMD and cache-friendly data…

Paper and discussion history. A mention is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by 0x000xca0xfe

Sat, 30 Aug 2025 15:48:29 GMT

Bit manipulation instructions are great for high-performance code, too, because they allow conditional computing without branching. Some real-world examples in simdjson: https://arxiv.org/pdf/1902.08318

Paper and discussion history. A mention is not an endorsement.

Parsing Gigabytes of JSON per Second — HN submission

Wed, 11 Sep 2024 13:57:06 GMT

Parsing Gigabytes of JSON per Second

5 points; 1 discussion reply on HN. Paper and source history. A submission is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by winwang

Sat, 09 Mar 2024 19:39:32 GMT

If people like stuff like this, the simdjson paper uses similar techniques, is extremely well-written and has great examples. Paper: https://arxiv.org/abs/1902.08318 Github: https://github.com/simdjson/simdjson

Paper and discussion history. A mention is not an endorsement.

Parsing Gigabytes of JSON per Second — HN submission

Thu, 21 Oct 2021 06:51:09 GMT

Parsing gigabytes of JSON per second

139 points; 79 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by Rendello

Sun, 03 Oct 2021 16:29:27 GMT

I find these optimizations fascinating. Anyone familiar with Lemire likely knows about this, but I listened to a podcast episode[1] with him a few days ago and learned about `simdjson`, the tool he authored that parses JSON at 25x the speed of the standard C++ library.[2][3] It's worth looking at if you're into this sort of thing. 1. https://corecursive.com/frontiers-of-performance-with-daniel... 2. https://www.youtube.com/watch?v=wlvKAT7SZIQ 3. https://arxiv.org/pdf/1902.08318.pdf

Paper and discussion history. A mention is not an endorsement.

Parsing Gigabytes of JSON per Second — HN submission

Tue, 05 May 2020 14:36:29 GMT

Parsing Gigabytes of JSON per Second [pdf]

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by aristus

Sat, 27 Jul 2019 15:00:40 GMT

Lemire is one of the leading experts on string matching and the author of several core libraries you probably use every day. edit fine, so instead maybe click on the links in the post to see that this article is just one of a series. He's probably tired of copy-pasting the specs of his reference hardware (Skylake https://arxiv.org/pdf/1902.08318.pdf) since all he's concerned about is the relative performance of different software. There is a difference between "I'm being dumb because I don't know what I'm doing" and "I'm being lazy because I've done it 1,000 times and the target audience…

Paper and discussion history. A mention is not an endorsement.

Parsing Gigabytes of JSON per Second — mentioned by glangdale

Tue, 26 Mar 2019 14:15:53 GMT

(the broader comparison is in Table 9 at https://arxiv.org/pdf/1902.08318.pdf)

Paper and discussion history. A mention is not an endorsement.