JSON Viewer

A fast tree viewer for big JSON files

JSON is easy to read when it is a dozen lines long and almost impossible when it is a 40 MB API dump, a GeoJSON export or a browser HAR file. Text editors struggle with files that size, and most online viewers either upload your data or freeze the tab while they build thousands of HTML elements. This JSON viewer is designed for exactly that situation: drop the file and it is parsed locally, then displayed as a collapsible tree where only the rows currently on screen are drawn. Whether the document has a hundred nodes or several million, scrolling and expanding stay responsive.

Each row shows the key or array index, a color-coded value and, for objects and arrays, the number of keys or items they contain. Click any row to select it and toggle it open, or use the keyboard: the arrow keys move and expand, Page Up and Page Down jump a screen at a time, and Enter toggles the current node. Expand all and Collapse all work on the whole document, with a safety limit so a huge file cannot lock up the page.

Search and copy paths

The search box looks through every key and value in the document, including nodes that are still collapsed. Press Enter to jump to the next match and Shift+Enter to go back; the viewer expands the parents of each match, scrolls it into view and highlights the matching text. This makes it quick to find a specific ID, email address or error code buried deep inside a nested response.

When you select a node, its full path appears below the tree. Choose the notation you need — JavaScript, JSONPath, JSON Pointer, jq or Python — and copy it with one click, or hover a row and use its copy path button. Keys containing spaces, dashes or other special characters are quoted and escaped correctly for each format, so the copied path can be pasted straight into code, a jq command, a test assertion or a JSON Patch operation. Copy value copies the selected string as plain text, or any object or array as formatted JSON.

Private and works offline

Everything happens in your browser. The file is never uploaded, there is no account and nothing is stored, so it is safe to inspect production logs, customer exports or responses that contain tokens. Newline-delimited JSON (NDJSON or JSON Lines) is recognized automatically and shown as an array, and invalid input is reported with the line and column of the first error. If you need to reformat, minify or sort the keys of a document rather than browse it, use the JSON Formatter instead.