Dev tools · alternatives · 2026
24 alternatives to Duper – The Format That's Super
An MIT-licensed human-friendly extension of JSON with quality-of-life improvements (comments, trailing commas, unquoted keys), extra types (tuples, bytes, raw strings), and semantic identifiers (think type annotations). Built in Rust, with bindings for Python and WebAssembly, as well as syntax highlighting in VSCode. I made it for those like me who hand-edit JSONs and want a breath of fresh air. It's at a good enough point that I felt like sharing it, but there's still plenty I wanna work on! Namely, I want to add (real) Node support, make a proper LSP with auto-formatting, and get it out…
Duper is a human-friendly JSON extension that adds quality-of-life features like comments, trailing commas, and unquoted keys, plus extra types including tuples and bytes. Built in Rust with Python and WebAssembly… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
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JSONverify▲92A web tool that validates and format JSON objects
2021 · jsonverify.com · its alternatives →
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the JS/Node.JS library for encoding complex and unconventional data structures. Support for BigInts, TypedArrays, null, undefined, and Symbol. Multiple flavors available. - DO-SAY-GO/WeirdJSON
2020 · github.com · its alternatives →
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Very low footprint DOM-style JSON parser written in portable ANSI C - json-parser/json-parser
2012 · github.com · its alternatives →
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JSON Master▲82Format, repair, convert, and visualize JSON, XML, YAML, CSV, and TOML. Free developer platform with advanced visualizers and AI-powered syntax repair.
2020 · jsonmaster.com · its alternatives →
- 7
JSON5 — JSON for Humans. Contribute to json5/json5 development by creating an account on GitHub.
2012 · github.com · its alternatives →
- 8
Hi HN, Simple online tools on the web have become unnecessary greedy. For example, * https://jsonformatter.org/ displays 7 ads on page load * https://convertcase.net/ had 4 ads plus a Google Vignette. And many more sites do the same thing. It's just noisy, which is why I created this VS Code Extension where you don't need to even leave your editor for your small web operations. I also built a Desktop app and an online version, which can be reached or downloaded at smallonlinetools.net. Both of which will be ad-free forever. So far smallonlinetools.net has over…
2024 · marketplace.visualstudio.com · its alternatives →
- 9
Fast, correct Python JSON library supporting dataclasses, datetimes, and numpy - ijl/orjson
2018 · github.com · its alternatives →
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un-opinionated S-expression syntax and macro system for JavaScript - anko/eslisp
2015 · github.com · its alternatives →
- 11
Quickly formats JSON with a simple right click, no copy
2023 · chromewebstore.google.com · its alternatives →
- 12AF
Serialization framework with some interesting numbers: 10-20x faster on nested objects than json/protobuf. Technical approach: compile-time codegen (no reflection), compact binary protocol with meta-packing, little-endian layout optimized for modern CPUs. Unique features that other fast serializers don't have: - Cross-language without IDL files (Rust ↔ Python/Java/Go) - Trait object serialization (Box) - Automatic circular reference handling - Schema evolution without coordination Happy to discuss design trade-offs. Benchmarks:…
Oct 2025 · fory.apache.org · its alternatives →
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Weird JSON▲19the JS/Node.JS library for encoding complex and unconventional data structures. Support for BigInts, TypedArrays, null, undefined, and Symbol. Multiple flavors available. - DO-SAY-GO/WeirdJSON
2022 · github.com · its alternatives →
- 14IM
2024 · prakhar897.github.io · its alternatives →
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Millions of developers have used quicktype to generate ten billion lines of typesafe models, serializers, and validators from JSON, JSON Schema, and GraphQL in TypeScript, Python, Swift, C#, Go, Rust, Kotlin, Java, C++, Zod and more. Use it in the browser, from the command line, or give it to your A
2017 · quicktype.io · its alternatives →
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JSON extended with pure functions. Contribute to VictorTaelin/LJSON development by creating an account on GitHub.
2015 · github.com · its alternatives →
- 17
A crate to protect against malicious JSON payloads. - ADD-SP/json-threat-protection.rs
2024 · github.com · its alternatives →
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A relaxed, user-friendly json-like data format. Contribute to polymonster/jsn development by creating an account on GitHub.
2019 · github.com · its alternatives →
- 19
First time ever working on something like this, check it out
2024 · github.com · its alternatives →
- 20
Efficient JSON editing with one-click formatting & search
2025 · its alternatives →
- 21
Free JSON toolkit — format, validate, diff & repair
Jul 2026 · freejsonparser.com · its alternatives →
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JSONSift▲10Free developer tools that run entirely in your browser
Jun 2026 · jsonsift.com · its alternatives →
- 23
Format, validate and minify JSON instantly
Jun 2026 · tools.bmjapps.in · its alternatives →
- 24
Open source, privacy-friendly, installable json formatter
2020 · jsonformatter.com · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →