Short answer
Choose JSON Crack when a diagram explains the data better than a tree, or when you want generated types, a JSON Schema or an exported image. Choose Blobster for documents larger than a few hundred kilobytes, for NDJSON logs, HAR files and OpenAPI specs, and when you need to edit or redact before sharing.
Key points
- JSON Crack’s FAQ says its visualiser handles approximately 300 KB, depending on the data and your hardware.
- Both process pasted data in the browser. JSON Crack’s privacy policy says its website may use Google Analytics.
- JSON Crack is open source (Apache-2.0) and also offers a VS Code extension and a Chrome extension.
- Blobster parses files up to 25 MB by default and streams large CSV and NDJSON files into a table.
At a glance
| Criterion | Blobster | JSON Crack |
|---|---|---|
| Main view | Tree, table, raw and format previews | Interactive graph, plus a tree view |
| Formats | JSON, YAML, TOML, XML, CSV, TSV, NDJSON, JWT, HAR, OpenAPI, .env and Markdown | JSON, YAML, CSV and XML |
| Size | 25 MB parse limit by default, adjustable; larger files open in Raw first | About 300 KB for visualisation, according to its FAQ |
| Output | Copy values, subtrees, rows, paths and redacted output | Export the graph as PNG, JPEG or SVG |
| Developer tools | JSONPath queries, structural compare, inferred JSON Schema, and paths as JSONPath, jq or JavaScript | TypeScript, Go and Rust types, JSON Schema, mock data, jq and JSON path |
| Editing | Edit values, rows and raw text locally | Text editor that updates the graph as you type |
| Privacy | No analytics or telemetry in the extension | Editor data stays in the browser; the website may use Google Analytics |
| Source | Not published | Open source, Apache-2.0 |
Where JSON Crack is stronger
JSON Crack is built for seeing structure. Nested objects become connected nodes you can pan, zoom and collapse, which explains an unfamiliar payload faster than expanding a tree one level at a time. You can export the graph as PNG, JPEG or SVG for a design document or a ticket.
It also has tools Blobster lacks: converters between JSON, YAML, CSV and XML, generated TypeScript interfaces, Go structs and Rust serde types, JSON Schema validation, mock data and jq commands. The project is open source, and the same graph is available in VS Code and as a Chrome extension that renders JSON pages.
Where Blobster is different
Blobster is a workbench for reading and changing data rather than drawing it. Tree and table views suit arrays of records, where a graph turns into hundreds of boxes. You can search keys and values, edit locally, copy an exact path and copy a redacted version for a ticket.
It also opens formats JSON Crack does not list, including NDJSON and JSONL logs, HAR captures, OpenAPI specs, TOML and .env files, and it can compare two files structurally and run JSONPath queries across a document.
Size changes the answer
JSON Crack’s FAQ puts its limit at about 300 KB, depending on the data and the hardware, and a graph of a large export would be hard to read anyway. Blobster parses files up to 25 MB straight away by default, opens larger ones in Raw first, and streams CSV, TSV and NDJSON files over about 1 MB into a table.
Privacy is close, with one difference
JSON Crack says data pasted into its editor is processed in the browser and not stored on its servers. Its privacy policy also says the website uses cookies and may use Google Analytics. Blobster’s extension has no analytics or telemetry. If your policy cares about what runs next to the data as well as where the data goes, that difference matters.
A simple decision rule
Reach for JSON Crack to explain a structure to someone or to generate types from a sample. Reach for Blobster to investigate a real payload, especially a big or sensitive one, and to share a redacted piece of it.