I created subtitletools.com back in January 2017.
A few months before that I met a girl while studying abroad in China.
We enjoy watching movies together, but usually Chinese subtitles come in formats that wouldn't display correctly on our TV.
I created a basic converter to fix this problem and put it on the internet.
It turned out more people had this problem, and the site started organically attracting more and more visitors.
I've kept working on the site since then, mostly on tools I needed myself, but also on tools and features requested by users. It kind of snowballed since then, and now the website helps more than 75,000 unique users per month.
Subpictures are subtitles that contain pictures.
The "sub/idx converter" and the "sup converter" convert these subtitles to srt.
In the last 30 days, 21,751 subpicture files were uploaded (201.9 gb, 725 per day)
The tools extract the images from the subtitles, and then use OCR to read the text from the images.
In the last 30 days, 13,096,388 images were extracted and OCR'd (32.7 gb, 436,546 per day)
OCRing is hard work. When the OCR is running, it uses 100% of a CPU core until it is done. To support the heavy load, I spread out the work over multiple servers.
In the last 30 days, 1535 hours were spent OCRing (51 hours per day)
The site supports a wide variety of plain text subtitles.
The plain text subtitle tools include all tools, except the subpicture tools described above.
In the last 30 days, plain text tools were used 261,807 times (8,727 times per day)
You can upload multiple files at the same time when using these tools.
In the last 30 days, a total of 452,322 files were uploaded (41.8 gb)