Format, convert, validate and inspect data or source code in one private workspace. Connect JSON, CSV, YAML and TOML workflows, query data, inspect tokens and preview code changes before applying them.
Your content stays on your device Free, with no account
Inspect. Convert. Validate. Keep building. On-device processing · no uploads
No file selected.
Paste source or open a UTF-8 file up to 1 MiB. Working document and applicable output: 200,000 UTF-16 units. Inputs are never executed.
0 UTF-16 units0 UTF-8 bytes0 lines
Choose a step, paste source and preview. Apply only the output you want to keep.
Your first preview pins a baseline. Compare edits against it or use a separate comparison input.
Reports cannot replace source accidentally. Transformations apply only when you choose Apply to source.
Data and source stay on this page. JWT decoding does not verify signatures. Formatting/minification does not establish correctness. SQL, .env expressions, HTML and JavaScript are never run. Schema validation uses the standalone tool’s supported Draft-07 subset; no remote references or imports are fetched.
Operations retain the standalone tools’ input and format limits. CSV/JSON conversions can change representation or types as explained in the result. Output above the working limit is rejected, never truncated. Regex has a 3-second deadline; worker operations have 7 seconds. XML uses the browser’s native parser with bounded input and a safe preflight. No automatic source storage.
A FEW SIMPLE STEPS
How to use Developer Studio
Paste source, import a UTF-8 file or load an example matching the chosen operation.
Select formatting, conversion, validation, querying, encoding, generation or inspection. Configure the relevant options and any secondary input.
Preview the result. Apply a transformation to continue with its output, or copy/download a read-only report. Undo or restore the pinned baseline when needed.
Compare edits, download source/results with appropriate extensions, or clear the studio to release source and history.
PRIVATE BY DESIGN
Why use this tool?
Your source, credentials and data are never uploaded to any server. Processing uses self-hosted libraries and local workers with cancellable deadlines; XML uses the browser’s native parser after a bounded preflight. Connected steps avoid repeatedly copying data between websites. No accounts, remote schema references, tracking endpoints or automatic source storage are used.
Tool inputs stay in your browser. Only your theme preference is saved on this device.
A few things worth knowing
What is included?
JSON format/minify/syntax validation; JSON↔CSV, JSON↔YAML and JSON↔TOML; JSON Schema validation and JSONPath querying; XML, SQL and .env formatting; HTML/CSS/JavaScript minification; code diff and regex testing; URL/Base64/Base64URL/HTML entity encoding; JSON/JavaScript string escaping; query-string parsing; JWT inspection, text hashing and UUID v4 generation; timestamps, cron, colors, storage-unit conversion and a local HTTP status reference. Standalone tools remain available with their dedicated interfaces.
How do connected workflows work?
Preview reads the current working source and leaves it unchanged. Apply replaces it with a transformation so the next step can use the result immediately—for example, CSV→JSON→JSONPath→JSON formatting. Reports cannot be applied accidentally. JWT inspection offers an explicit payload handoff for further JSON work; decoded claims remain unverified. Undo/redo is bounded to 20 snapshots and two million UTF-16 units. Your first preview pins a baseline for comparisons or restoration.
Do conversions preserve every value?
Format support and limits match the shared standalone engines. JSON formatting preserves original number spellings and duplicate members while reporting duplicates. Conversions can reject duplicate keys, unsupported types or unsafe numeric ranges instead of silently coercing them. CSV→JSON keeps field values as strings. JSON→CSV can protect spreadsheet formula-like string cells with an apostrophe; this changes the exported string representation. YAML/TOML conversion supports the documented subsets, not arbitrary executable tags or imports. Review each preview.
Is a decoded JWT trusted?
No. Decoding does not verify signatures, authenticate users or establish authorization. Algorithm and timing claims are untrusted data and depend on the device clock. The explicit payload handoff only transfers decoded JSON into the editor; it does not verify it. Keep tokens and downloaded claims private.
Does Developer Studio execute source or fetch references?
No input code, SQL, HTML, .env expression, cron command, URL or decoded script is executed. Regex runs in a disposable worker. Schema validation uses the standalone Draft-07 subset, with no remote or recursive references, coercion or mutation. JSONPath uses its RFC 9535 subset without JavaScript evaluation. HTTP results come from a labeled local registry snapshot; no destination is contacted.
What limits apply?
Working source and applicable output: 200,000 UTF-16 units. File import: valid UTF-8 up to 1 MiB. Existing per-tool limits still apply: schema/query/code parsers may allow less, along with limits on nesting, rows, tokens and matches. Larger transformation output is rejected rather than truncated; reports are bounded to one million units. Regex stops after three seconds, and worker operations after seven. XML uses the native browser parser with bounded 100,000-unit input and safe preflight checks. Working line endings use LF.
What should I know about formatting and minification?
Formatting is not proof that code is correct or safe. Minification parses source without executing it; changing HTML whitespace can affect rendering, so that option is explicit. SQL formatting is not database validation. XML rejects unsupported or unsafe constructs and preserves protected text sections. Review and test generated code before using it.
Are hashes, UUIDs and time conversions suitable for every purpose?
UUID v4 uses secure browser randomness without a weak fallback. Hashes cover UTF-8 text with LF-normalized line endings; MD5 and SHA-1 are legacy checksum choices, not password hashing. Timestamp inputs require explicit units or an ISO timezone. Cron is a five-field UTC preview with no scheduler or job creation; actual scheduler timezones and daylight-saving rules can differ. Byte conversion distinguishes decimal and binary units.
Will my source be saved when I leave?
No. Source, schema/comparison text, queries, previews and edit history are held only in this page. Clear studio stops pending workers, invalidates late file reads, clears source and secondary inputs, and revokes application-held download URLs. Leaving the page also cleans up. Download files if you want to keep your work; already downloaded files remain on your device.
