OTL
About us

The free tool library that never asks for your files

Open Tools Library is a growing collection of everyday tools — merging a PDF, signing a document, converting an image — that run entirely inside your browser. No upload, no account, no watermark, no cost. This page explains why that's the whole point, how it's technically possible, everything you can already do here, and what's coming next.

100% client-sideNo signup, everNo file ever uploadedFree, permanently

Why we exist

Search for almost any everyday file task — "merge PDF," "compress image," "convert to Word" — and the results are dominated by sites that ask you to upload your file to a stranger's server first. Some queue you behind a daily limit. Some quietly attach a watermark unless you subscribe. Nearly all of them want an account, an email address, or both, before they'll do something as simple as combining two PDFs.

None of that friction is actually necessary. A modern browser is powerful enough to merge, split, compress, sign, and convert files entirely on its own — no server required. Open Tools Library is built around that fact. Every tool here does its work using JavaScript running on your own device, the same way a desktop application would, except there's nothing to install and nothing to sign up for.

The goal is simple: become the one link you bookmark for any everyday tool, instead of searching fresh every time and gambling on whichever ad-choked, upload-your-file site ranks highest that week.

How it actually works

When you drop a file into a tool on this site, your browser reads it directly into memory using the File API — the same browser-native mechanism any app uses to let you pick a file. From there, everything happens locally: pdf.js (the same rendering engine behind Firefox's built-in PDF viewer) decodes and displays PDF pages, pdf-lib writes new PDF bytes back out, and the browser's own Canvas API handles image decoding and re-encoding. At no point does your file get serialized into a network request.

Some tools go further. The PDF Editor and Sign PDF tools track every element you place in the exact coordinate space of the underlying PDF page, so what you see while editing is what ends up in the exported file — no separate upload-and-reprocess step to introduce drift between preview and output. The PDF to Word tool falls back to Tesseract.js, a WebAssembly build of the Tesseract OCR engine, when a scanned PDF has no text layer to extract — that's genuine optical character recognition, running as compiled WebAssembly in your tab, not a server-side call.

The only network request any tool makes is a one-time download of the OCR engine itself (from a public CDN, the first time you use OCR) — never your file. The full breakdown of exactly what each tool does and doesn't send anywhere is in our Privacy Policy.

Every tool you can use today

PDF Tools is the first category we built out fully, and it's live right now with 9 tools covering the most common things people need to do with a PDF — several of which also show up under Image Tools, File Converters, and Security & Privacy since they double as image and security tools too.

Prefer to browse everything in one place, with filters? See the full tools directory.

The full roadmap, category by category

Open Tools Library is being built out deliberately, one category at a time, finishing each before starting the next. That's a slower path than launching every category half-built on day one — we think it's the only way every tool that does ship is actually solid. Here is every category we're planning, exactly as it stands today:

Built on open source

None of this would be possible without the open-source projects that do the actual heavy lifting inside every tool. We think that's worth crediting explicitly rather than burying in a license file:

pdf-lib

Creates and edits PDF documents directly in the browser — the engine behind merging, splitting, signing, and editing.

pdf.js

Mozilla's PDF rendering engine — the same technology behind Firefox's built-in PDF viewer — used to render and read PDF pages.

JSZip

Bundles multiple output files (like a batch of converted images) into a single downloadable .zip, entirely client-side.

Tesseract.js

A WebAssembly build of the Tesseract OCR engine, used as a fallback to read text out of scanned, image-only PDFs.

Every one of these runs entirely on your device alongside our own code — none of them phone home with your file, either.

How we make money (and how we don't)

Running and building a site costs something, even when every tool on it is free. We cover that with advertising — currently supplemented by Google Analytics to understand which tools actually get used, with Google AdSense planned to support it financially — never with subscriptions, never by selling data.

That second point isn't just a promise, it's a structural fact: since your files are processed entirely on your device and never reach our servers, there is no file data of yours for us to collect, analyze, or sell in the first place. The full detail on exactly what is and isn't collected — and how to opt out of analytics or personalized ads — is in our Cookie Policy and Privacy Policy.

This model doesn't change as more categories launch. Every tool that ships free — today, and in every category still marked "Soon" above — stays free.

Our privacy commitment

Privacy on Open Tools Library isn't a toggle you switch on, or a setting buried in an account you had to create anyway — it's the architecture. There is no upload button that sends your file anywhere, so there's no "opt out of file sharing" checkbox to forget, and no server-side copy that could later leak, get subpoenaed, or be used to train a model.

That covers the actual files you process. For the handful of things the site does need to operate — anonymous traffic analytics, and eventually advertising — we've published our Privacy Policy, Cookie Policy, and Terms of Service in full, in plain language, rather than a wall of boilerplate designed to be skipped.

Why accuracy is non-negotiable

A tool that's private but wrong isn't actually useful — a merged PDF with a corrupted page, or a signature placed a few millimeters off, defeats the point just as much as a tool that uploads your file somewhere it shouldn't. So every tool here is built around exact coordinate math (PDF points converted precisely to on-screen pixels and back), not approximations, and tested by re-parsing its own output byte-by-byte to confirm the result actually matches what was requested — not just that it looked right on screen.

If you ever run into a tool that doesn't behave the way it should, that's genuinely useful to know about — tell us on the Contact page and we'll look into it.

Frequently asked questions

Who builds Open Tools Library?

A small, independent team — not a large company. That's a deliberate choice: it keeps the site focused on shipping tools that are genuinely useful rather than chasing every possible feature at once.

How do you decide what tool to build next?

Whatever's most useful to the most people, within the category currently in progress. Once a category has a solid, accurate set of tools, we open the next one rather than spreading thin across many half-finished categories at once.

Can I actually trust the output of these tools?

That's the standard we hold every tool to before it ships — see "Why accuracy is non-negotiable" above. If something ever looks wrong, we want to know: use the Contact page and we'll dig into it.

What happens to my files after I close the tab?

Nothing, because there was never anything to clean up. Files are read into your browser's memory for the duration of the tool, and that memory is released the moment you close the tab or navigate away. Nothing was ever written to a server to begin with.

Do you use my files to train AI or for any other purpose?

No. We never receive your files at all, so there's nothing to train on, analyze, or repurpose. Every tool runs entirely client-side.

Is Open Tools Library itself open source?

The site is built on top of open-source libraries (credited above), which we're grateful for and try to give visibility to. The site's own codebase isn't currently public.

How do I suggest a tool or report a bug?

The Contact page has dedicated options for both — tool requests and bug reports go to a real inbox someone actually reads.

Will tools ever move behind a paywall?

No. Every tool that launches free stays free, permanently. The site is funded by advertising, not subscriptions, so there's no pressure to convert free users into paying ones.

Ready to try it yourself?

No account, no upload, no catch — pick a tool and see for yourself.

Built independently.Available everywhere, in every browser.Read the fine print in our Privacy Policy.