jsonl.co
Free browser-based JSONL viewer and editor that processes files locally, for developers working with JSONL and NDJSON data.
jsonl.co is a browser-based JSONL viewer and editor built and maintained by Jerry Fan, an independent developer. It opens .jsonl, .ndjson, .json and .txt files, shows raw text beside parsed JSON, validates edits in real time for smaller files, and exports with one click. The vendor states it handles files up to 1GB and beyond using streaming, and lists converters, a splitter, a merger and a VS Code extension. The vendor describes it as Free Forever, with processing done locally in the browser. The interface is offered in 12 languages including English. Ads are served through Google AdSense. Pages read on 2026-11-09.
- ✓The vendor describes the service as Free Forever
- ✓File processing is stated to run locally in the browser, and files are not uploaded to the vendor's servers
- ✓Streaming reads are stated to handle JSONL files up to 1GB and beyond
- ✓Includes JSONL, JSON and CSV converters plus a formatter, validator, splitter and merger
- ✓The interface is offered in 12 languages, including English
- ✓Terms of Service state that users retain full ownership of files they process
- ×Direct editing of raw JSONL text is described for smaller files
- ×The site displays advertisements through Google AdSense, which may use cookies and web beacons
- ×Terms of Service state the service is provided 'as is' without warranties of any kind
- ×It is described as an ongoing solo project maintained by one independent developer
- ×The site uses Google Analytics and Plausible Analytics for usage statistics, and cookies for site functionality and advertising
About jsonl.co
jsonl.co is a browser-based JSONL viewer and editor built and maintained by Jerry Fan, an independent developer. It opens .jsonl, .ndjson, .json and .txt files, parsing each line as JSONL, and shows raw text on the left with parsed JSON on the right. It reads files in chunks using streaming technology and is stated to handle files up to 1GB and beyond. The site also lists converters between JSONL, JSON and CSV, a formatter, a validator, a splitter, a merger and a VS Code extension. The vendor states that file processing happens locally in the browser. The vendor describes the service as Free Forever. The site shows advertising through Google AdSense.
Key Features
Best For
Southeast Asia Fit
The vendor states that file processing runs locally in the browser and that files are not uploaded to its servers. The site interface is offered in ZH, EN, JA, ZH-TW, DE, FR, KO, ES, PT, IT, NL and PL. The vendor describes the service as Free Forever, so there is no published price in any currency. Whether jsonl.co serves specific Southeast Asian markets is an open question put to the vendor; see the FAQ. Whether the interface is available in Thai, Indonesian, Vietnamese or another Southeast Asian language is also an open question put to the vendor; see the FAQ. Disclosure: jsonl.co asked to be listed and submitted itself for listing on 2026-11-08. This profile was built from jsonl.co's own public pages and sent to the vendor for fact-checking; listing is free and does not affect any score or ranking.
Integrations
- Other
- VS Code
This profile was researched and written with AI from jsonl.co's public pages, and AI assistants quote pages on this site. Something wrong or out of date? Email info@software-listing.com with this page and a public source. We fix errors in what we published at no charge; updates and additions come with the one-time USD 10 listing fee, for 12 months.
How listings and corrections work →- ↗The homepage describes the supported file formats, streaming of files up to 1GB and beyond, the side-by-side editor with real-time validation, one-click export, the converter and utility tools, and the VS Code extension.verified 2026-11-09
- ↗The homepage describes the service as Free Forever, states that processing happens locally in the browser, and says the site is available in multiple languages.verified 2026-11-09
- ↗The about page says jsonl.co is built and maintained by Jerry Fan, an independent developer, as an ongoing solo project, with a stated mission to make working with JSONL effortless.verified 2026-11-09
- ↗The privacy policy states files are never uploaded, and lists local storage for preferences, Google Analytics, Plausible Analytics, Google AdSense, Cloudflare, cookies and consent handling for EEA, UK and Swiss visitors.verified 2026-11-09
- ↗The Terms of Service, last updated February 2026, state that users retain ownership of their files, that the service is provided 'as is' without warranties, and that the site's design, code and content are protected by intellectual property laws.verified 2026-11-09
"Verified" means read on the vendor's own published pages on the date shown. We do not run hands-on tests, and a statement a vendor confirmed to us directly is labelled as vendor-confirmed. Software-listing.com is independent and may earn affiliate commissions from some links.
Related Analysis & Guides
The questions operators actually ask.
What is jsonl.co?
jsonl.co is a browser-based JSONL viewer and editor. It opens .jsonl, .ndjson, .json and .txt files and shows raw JSONL beside parsed JSON. It is built and maintained by Jerry Fan, an independent developer.
Does jsonl.co cost anything?
The vendor's homepage describes it as Free Forever and a completely free online JSONL viewer and editor. The site is supported by advertising through Google AdSense.
Are my files uploaded to jsonl.co servers?
The vendor states that all processing happens 100% locally in the browser, and its privacy policy says files are never uploaded to its servers. The privacy policy was last updated in October 2026.
Which markets does jsonl.co serve, and does the vendor have any presence or support in Southeast Asia?
Not verified yet. The vendor has been asked which markets it serves and whether it has any presence or support in Southeast Asia.
Is the jsonl.co interface available in Thai, Indonesian, Vietnamese or other Southeast Asian languages?
Not verified yet. The homepage lists localized versions in zh, en, ja, zh-tw, de, fr, ko, es, pt, it, nl and pl. The vendor has been asked whether any Southeast Asian language is offered or planned.
What file formats and tools does jsonl.co support?
It supports .jsonl, .ndjson, .json and .txt files. Listed tools include JSONL to JSON, JSON to JSONL, JSONL to CSV and CSV to JSONL converters, a formatter, a validator, a splitter and a merger. A VS Code extension is also listed.