Show HN: Convert Large CSV/XLSX to JSON or XML in Browser

41•Botlabs•10mo ago

Hello HN, I'm excited to share a project I've been working on: A simple, fast way to process huge CSV and XLSX files directly in your browser and export them as clean JSON or XML

Here's a few things that makes this converter different: - runs in the browser - all parsing and conversion is client side can handle data any size data - automatically detects delimiters, encodings, and data types as it parses - Live preview with column renaming, search/replace, and data cleanup - Export to JSON or XML — clean, structured output that can be used for API or Databases

backstory: I built this tool for myself. I work with massive CSV and TXT files, some over 10GB, and opening them in Excel would freeze my laptop, some of the online converters only limits to a certain size, so I started learning Python and pandas but ended up wasting so much time trying different delimiters or fixing badly structured data just to make it usable, and I thought this would be a really fun project to build

I'd love some feedback. Thank you

URL: https://csvforge.com

Comments

sverhagen•10mo ago

"Runs in the browser" and "client side" isn't as much of a selling point to me as it's made out to be. It's a claim that I can't really validate until it's too late. If it's a commercial service I'm going to have to pay for, then maybe you should go all the way in gaining my trust with whatever safeguards it takes, so that I no longer care if I upload my data to your server or not.

rustc•10mo ago

> then maybe you should go all the way in gaining my trust with whatever safeguards it takes

What kind of safeguards are possible with a web app?

sverhagen•10mo ago

I think this comes down to legally-enforceable contracts with some teeth. A lot of business seem okay to trust Google's cloud products, or Microsoft's? I think as private person with limited means for litigation, you're likely sol.

hahn-kev•10mo ago

Yeah I really wish there was a way for this to be enforced by the browser that the end user could trust. It would have to be a standard, but outside of opening dev tools and toggling offline mode there's no way to be sure.

The funny thing is that it feels safer to download a desktop app and give it the same data even though it's usually much harder to validate if it's shipping your data somewhere else.

strogonoff•10mo ago

There’s a cheap trick to make sure a website that claims to do everything client-side actually does everything client-side:

1. Open the site in an incognito window.

2. Turn off your Internet.

3. Do what you’ve got to do.

4. Close browser window.

As a bonus, and this makes it better than just flipping the offline switch in developer tools, if you turn off Internet in a way that keeps the browser thinking it’s online, you can also peek at whether any network requests are made (for pathological cases where the app does everything locally but phones home anyway).

Botlabs•10mo ago

Sure, but you can validate it dev tools exist for a reason. Honestly, I just can’t afford the storage costs if users are uploading 50GB+ CSVs. It’d be a huge strain on any server, not to mention painfully slow for users. Running everything client side was the easiest and most practical way to build this MVP at least for me thanks for the feedback

o11c•10mo ago

"Large" generally means "bigger than RAM"; 10GB is medium-sized these days since it fits in most people's RAM. Does the browser actually have the (web worker?) APIs needed to stream and "upload" and "download"?

shubhamjain•10mo ago

I don't get it. Are JSON and XML files more friendly to import vs CSV files? I always assumed CSVs were the standard. Any reasons to prefer structured formats?

Shameless plug: I am working on a similar problem of Excel not being a great tool for large datasets. My desktop app[1] lets you import raw data files and query them using SQL. (The website needs to be updated, the app looks much better than the current screenshots).

[1]: https://textquery.app

Botlabs•10mo ago

yes they are a lot easier to work with when inserting into the database

snappr021•10mo ago

This type of thing is fairly trivial to create with ChatGPT running entirely locally in HTML.

A couple of kb of open standard vanilla js that does some simple things faster than legacy spreadsheets etc ever could.

Even to the point of creating invoices, reports etc based on standard filters stored in local storage…

oschvr•10mo ago

Looks like you made it in lovable. It has that characteristic UI.

If so, how much time did it take you?

Botlabs•10mo ago

thanks for your comment, it took me almost 3 weeks to build this

constantcrying•10mo ago

I think it should go without saying, but never use this with anything more relevant than a hobby project.

Doing this with any kind of data you don't fully own (e.g. data from your company) is a terrible idea, from so many standpoints. That it is "allegedly" running locally is not making it much better.

I think my question to OP is, who is this for. Any developer can write up a convert for his own datasets, in basically any case I can think of where you are handling large amounts of data you are building a pipeline to do cleanup, renaming, conversion, etc. Who wants to have a part of that pipeline be uploading the data into the browser?

GPT-5.4

Wikipedia in read-only mode following mass admin account compromise

The Brand Age

Pentagon Formally Labels Anthropic Supply-Chain Risk

Let's Get Physical

Hardware hotplug events on Linux, the gory details

A GitHub Issue Title Compromised 4k Developer Machines

Good software knows when to stop

Show HN: Jido 2.0, Elixir Agent Framework

Launch HN: Vela (YC W26) – AI for complex scheduling

Remotely unlocking an encrypted hard disk

Optimizing Recommendation Systems with JDK's Vector API

The Government Uses Targeted Advertising to Track Your Location

Datasets for Reconstructing Visual Perception from Brain Data

Nvidia PersonaPlex 7B on Apple Silicon: Full-Duplex Speech-to-Speech in Swift

Show HN: PageAgent, A GUI agent that lives inside your web app

Google Workspace CLI

A man who broke into jail

Greg Kroah-Hartman Stretches Support Periods for Key Linux LTS Kernels

OpenTitan Shipping in Production

World-first gigabit laser link between aircraft and geostationary satellite

Fast-Servers

Relicensing with AI-Assisted Rewrite

AI and the Ship of Theseus

Google Safe Browsing missed 84% of confirmed phishing sites

Comparing Python packages for A/B test analysis (with code examples)

Poor Man's Polaroid

Building a new Flash

AMD will bring its “Ryzen AI” processors to standard desktop PCs for first time

'Execution at sea': Was the Iranian ship sunk by US in the Indian Ocean unarmed?

GPT-5.4

Wikipedia in read-only mode following mass admin account compromise

The Brand Age

Pentagon Formally Labels Anthropic Supply-Chain Risk

Let's Get Physical

Hardware hotplug events on Linux, the gory details

A GitHub Issue Title Compromised 4k Developer Machines

Good software knows when to stop

Show HN: Jido 2.0, Elixir Agent Framework

Launch HN: Vela (YC W26) – AI for complex scheduling

Remotely unlocking an encrypted hard disk

Optimizing Recommendation Systems with JDK's Vector API

The Government Uses Targeted Advertising to Track Your Location

Datasets for Reconstructing Visual Perception from Brain Data

Nvidia PersonaPlex 7B on Apple Silicon: Full-Duplex Speech-to-Speech in Swift

Show HN: PageAgent, A GUI agent that lives inside your web app

Google Workspace CLI

A man who broke into jail

Greg Kroah-Hartman Stretches Support Periods for Key Linux LTS Kernels

OpenTitan Shipping in Production

World-first gigabit laser link between aircraft and geostationary satellite

Fast-Servers

Relicensing with AI-Assisted Rewrite

AI and the Ship of Theseus

Google Safe Browsing missed 84% of confirmed phishing sites

Comparing Python packages for A/B test analysis (with code examples)

Poor Man's Polaroid

Building a new Flash

AMD will bring its “Ryzen AI” processors to standard desktop PCs for first time

'Execution at sea': Was the Iranian ship sunk by US in the Indian Ocean unarmed?

Show HN: Convert Large CSV/XLSX to JSON or XML in Browser

Comments