The data-engineering toolboxthat never uploads your files
Format SQL, inspect and query Parquet, convert CSVs, profile schemas and more — all running 100% in your browser. Your files never leave your device. No upload, no server, no account.
- 35 data-engineering tools in one place
- Real Parquet & Avro — a Rust engine compiled to WebAssembly
- 100% client-side — your files never leave your device
Chrome 137+ · Firefox 129+ · No sign-up
Reads the formats you actually work with — locally, in your browser
- Parquet
- Avro
- CSV
- JSON
- JSONL
- YAML
- SQL
Stop pasting production data into random websites.
Data engineers paste a CSV, a Parquet file, a connection string or a JWT into whatever “free online converter” a search engine hands them. Those tools upload your data to someone else’s server — a compliance incident waiting to happen, and slow.
The tools that are safe — a local Spark job, a Polars snippet, a laptop CLI — mean writing code for something that should be a ten-second click.
DataEngUtils is the ten-second click that never uploads anything.
Your file goes from your disk to your browser. That’s the whole trip.
No upload, no server, no account. Here is exactly what happens when you drop a file.
- 1
Open the app in your browser
No install, no sign-up. The whole app is static files plus one WebAssembly engine — it runs on your machine, not ours.
- 2
Drop a Parquet, Avro, CSV or JSON file
The engine reads the bytes locally in a Web Worker. The file is never uploaded anywhere.
- 3
Inspect, query, convert — then export
Work with the results and save them. Nothing leaves your device, so it keeps working with your Wi-Fi off.
Do to Parquet what you do to text.
Inspect the schema, row groups and per-column stats. Query and filter rows. Profile nulls, ranges and distributions. Compare two pipeline versions for schema evolution. Prune the row groups a predicate can skip, and repair a corrupt file. All of it runs on a Rust engine (Apache Arrow) compiled to WebAssembly — the same technology behind parquet-wasm.
Private by architecture, not by promise.
The entire app is static files — there is no backend to upload to. Parquet, Avro, CSV and connection strings are read locally, and a strict Content-Security-Policy (connect-src 'self') makes “no exfiltration” a property of the build rather than a promise.
Works offline. Install it like an app.
Add DataEngUtils to your dock or home screen and it runs with no network at all after the first load. No account, no telemetry, no font or CDN calls — turn off your Wi-Fi and keep working.
Everyday data-engineering tools, in one place.
Format SQL across 9 dialects, validate JSON and YAML, parse cron schedules and JWTs, split connection strings, diff text, convert timestamps, hash values, and generate UUIDs or test data — all in one searchable app.
What’s in the box?
35 data-engineering tools you’ll use every week — 18 of them free.
Format & validate (4)
Convert (9)
Inspect & debug (16)
- Parquet InspectorFree
- Parquet Row Group PrunerFree
- Cron Expression ParserFree
- JWT DebuggerFree
- Connection String ParserFree
- Regex TesterFree
- Text Diff CheckerFree
- JSONL InspectorFree
- Data Type InspectorFree
- Parquet QueryPro
- Parquet Schema EvolutionPro
- Parquet Data ProfilerPro
- Parquet File RepairPro
- Avro File InspectorPro
- Avro Schema ValidatorPro
- SQL Query ExplainerPro
Encode & decode (2)
The convenience of an online tool, without the upload.
The tools that protect your data usually mean installing software. DataEngUtils gives you the browser workflow with a client-side engine.
| Online converters | Desktop toolkits | DataEngUtils | |
|---|---|---|---|
| Uploads your file | Yes | No | No |
| Works offline | No | Yes | Yes |
| Runs in the browser | Yes | No | Yes |
| Parquet / Avro engine | Rarely | Sometimes | Yes (WASM) |
| Data-engineering focus | No | Partial | Yes |
| Account required | Often | No | No |
Frequently asked questions
Is DataEngUtils free?
How do I unlock the Pro tools?
Does the licence work offline?
What is your refund policy?
What is the difference between Personal and Team?
Does DataEngUtils upload my files?
Open it. Drop a file. Nothing uploads.
18 tools will be free at launch — in your browser, no install, no sign-up, no card.
Works in Chrome 137+ and Firefox 129+. Install it as an app to run fully offline.