
Row Zero
Google Sheets
Microsoft Office Excel
Rons Data Edit
TablePlus
Tablecruncher
Modern CSV
Analyze large CSV files instantly in your browser with LeapRows. No upload required. Experience lightning-fast data processing and automation with DuckDB-WASM technology.

Decode and verify SSL/TLS certificates online. Extract X.509 details including issuer, validity, SAN, and fingerprint. Fast, secure, and browser-based.

Which is more popular?
Cert Decoder might be a bit more popular than LeapRows. We know about 1 link to it since March 2021 and only 1 link to LeapRows.
Website, pricing, platforms and company facts side by side.
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| Website | leaprows.com | certdecoder.com |
| Pricing | ||
| Platforms | — | |
| Company | Startup from Japan · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.


LeapRows is a blazing-fast, browser-based CSV analysis tool powered by DuckDB-WASM. It handles 1,000,000+ rows directly in your browser — no server uploads, no Python setup, no file splitting required. All processing happens locally on your device using WebAssembly (WASM) and the Origin Private...
Cert Decoder is a free online tool that helps you decode X.509 SSL/TLS certificates in PEM format. It instantly shows important information like the issuer, expiry date, SAN entries, and fingerprint. All data is processed locally in your browser, so nothing is ever sent or stored elsewhere.
What each product offers, as listed by its team.


Possible disadvantages
Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing LeapRows and Cert Decoder.
LeapRows's answer
LeapRows was born out of two frustrations: the "Python sharing problem" and server costs.
As an in-house SEO specialist, I frequently work with large CSVs exported from tools like Ahrefs, Google Search Console, and BigQuery — often hundreds of thousands of rows. For heavy lifting, I'd reach for Python (Polars), but Python has a steep barrier: environment setup, code adjustments, and a learning curve that made it impossible to share with non-engineer teammates.
Even for myself, I'd often think "do I really need to write Python just for this small transformation?" On top of that, frustrating edge cases — like type inference inconsistencies causing join errors on the same CSV from the same tool — kept piling up.
I wanted something as easy as a spreadsheet but capable of handling millions of rows. That's what LeapRows is.
Cert Decoder's answer:
I built certdecoder.com over the weekend for my own needs. Sometimes in my work, I need to verify and check certificate details.
LeapRows's answer
DuckDB-WASM, OPFS(Origin Private File System)
Cert Decoder's answer:
certdecoder.com was built using just JavaScript and HTML—simple, fast, and with all processing happening locally in your browser, so no certificate data is sent to any server
LeapRows's answer
Cert Decoder's answer:
certdecoder.com is primarily built for developers, sysadmins, cybersecurity enthusiasts, and DevOps engineers.
LeapRows's answer
Cert Decoder's answer:
Simple, fast, and reliable. Some similar tools can’t even decode basic certificates. I rigorously tested my tool with many real-world certificates and covered several edge cases where competitors fall short.
LeapRows's answer
Cert Decoder's answer:
certdecoder.com is primarily built for developers, sysadmins, cybersecurity enthusiasts, and DevOps engineers.
LeapRows's answer
LeapRows is a fully local, browser-based data tool powered by DuckDB-WASM that handles 1M+ row CSV files with blazing speed — no server, no uploads.
Share your experience with using LeapRows and Cert Decoder. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


I use this setup on LeapRows, a browser-based CSV tool I built on Vercel. - Source: dev.to / 6 months ago
Why? Because I built certdecoder.com and couldn’t find a decent place to submit it. So I said screw it — I’ll build my own. With blackjack and hookers. - Source: dev.to / over 1 year ago
When comparing LeapRows and Cert Decoder, you can also consider the following products.

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Synchronizing, online-based word processor, part of Google Drive.
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This lightweight, yet powerful CSV editor for Apple Mac helps you crunch all your tabular data.
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