AI & ML

Merging PDFs in the browser: no server, no upload

Merging PDFs sounds like server work, but the PDF format is just a structured binary file — and libraries like pdf-lib can read and write it entirel…

How to convert a PDF drawing into an editable DXF (without uploading your drawings)

If you work with construction or survey drawings, you have probably received a PDF and needed the same drawing in CAD. Print shops and cloud convert…

How to Get a Table Out of a PDF Without Uploading the File

Bank statements, invoices and supplier price lists often arrive as PDFs. When you need the numbers in a spreadsheet, the usual advice is to upload t…

I benchmarked 8 PDF extractors on 27 documents from 1 to 487 pages. Here's what broke, and what won.

I knew something was off when two numbers landed in the same afternoon. Every tool that reads the PDF text layer had scored exactly 0.00 on every ch…

Getting a PDF under 100 KB without turning the text into a picture

The form said "PDF, maximum 100 KB". My file was a one-page letter exported from Word, and it was several times that. I ran it through the first onl…

6 Free PDF Editors You Can Use in a Browser in 2026 (and What Happens to Your File in Each)

A fact-checked comparison of Smallpdf, iLovePDF, PDF24, Sejda, Adobe Acrobat online and PDFkind: free limits, what "free" actually unlocks, and whet…

Build a PDF Size Gate Before Your Document Pipeline Hits “Send”

The report rendered perfectly. The upload failed anyway. The bug was not in the report A successful build with an unusable artifact The job had done…

Бесплатная верстка и перевод книг: как я создал конвейер, работающий на видеокарте

Три месяца отладки, десятки книг и переход от Claude к локальным моделям. Рассказываю, как собрал открытый конвейер перевода и вёрстки книг: MinerU…

DataCube: A Relational Aggregation Operator Generalizing Group-By, Cross-Tab, and Sub-Totals (1997)

Abstract: Data analysis applications typically aggregate data across many dimensions looking for anomalies or unusual patterns. The SQL aggregate fu…

Auditable Monthly Report Archiving with PDF Text Extraction and OCR Verification

Short answer: extract embedded PDF text first, but make the decision per page rather than per file; send only pages that fail structural and content…

JSON Tiles: Fast Analytics on Semi-Structured Data (2021)

Abstract: Developers often prefer flexibility over upfront schema design, making semi-structured data formats such as JSON increasingly popular. Lar…

PDF to Excel in the Browser: Extracting Tables with JavaScript

Series: Building PdfWord — a free, no-backend PDF tools site (Part 11) "Convert my bank statement PDF to Excel" — one of the most requested features…

5 PDF Tools Nobody Else Gives You for Free (All Running 100% in Your Browser)

Series: Building PdfWord — a free, no-backend PDF tools site (Part 6) Most free PDF sites give you the same 10 tools: merge, split, compress, conver…

pdf.js split my numbers: rebuilding "CHF 15,000" from text items

We re-read a few hundred fee schedules every week, many of them published as PDFs, and check that a quoted amount is still on the page. One bank's p…

Why your photo-to-PDF pages come out in the wrong order (and how to sort them in the browser)

If you've built an "images to PDF" feature, you've probably had this bug report: "I picked page 1, 2, 3, 4 and the PDF came out 3, 1, 4, 2." Nothing…

Multi-Currency Invoice PDF Localisation Explained: Right-to-Left Layout Before Signing

Short answer: for multi currency invoice PDF localisation, generate from structured values, validate the right-to-left visual reading order, and onl…

Perseus: A Fail-Slow Detection Framework for Cloud Storage Systems (2023)

Abstract: The newly-emerging “fail-slow” failures plague both software and hardware where the victim components are still functioning yet with degra…

I Built a Browser-Local PDF Redaction Tool Because a Black Rectangle Isn't Redaction

A black rectangle can hide text on screen without removing the text stored inside a PDF. Someone may still be able to select, copy, search, or recov…

Bidirectional Type Slicing

Abstract: Development tools report what type an expression has, but not why it has that type. This paper develops a theory of type slicing that answ…

Adding page numbers to PDFs in your browser

Adding page numbers to PDFs in your browser Page numbers make a PDF easier to discuss. Instead of pointing someone to a section and asking them to s…

What Redaction Means in Node.js — PDF Lease Overlays Still Expose Text

TL;DR: Redaction removes sensitive content from a PDF. A black rectangle only covers that content on the page; the original text can remain selectab…

Merge PDFs in the browser with pdf-lib, and what it silently drops

You can merge PDFs entirely in the browser with pdf-lib . No server, no upload, about ten lines. We use exactly this in a small tool, so here is the…

Stuck Freight PDF Jobs: Debugging Progress Polling with Auditable Terminal States

Short answer: put a finite deadline around polling, model success and failure as explicit terminal states, and preserve an append-only event trail f…

Protocol-aware recovery for consensus-based storage (2018)

Программа поиска по PDF. Разбираем PageIndex, Streamlit и ссылки на страницы

«Срок гарантии — 18 месяцев». Красивый ответ. А если в договоре написано 12? Или число 18 стоит в разделе о хранении, а модель просто зацепилась за…

Puppeteer PDF headers and footers with page numbers: 7 traps

Adding "Page 3 of 7" to a Puppeteer PDF looks like one option. You set displayHeaderFooter: true , pass a footerTemplate , and render. Then the foot…

Monthly Game Reports — Merge One PDF or ZIP Separate Files

A monthly game report is rarely one document. Finance owns the revenue pages, live operations owns event results, and player support owns moderation…

Native vs OCR PDF Text in Node.js: Choose Page Indexing by Ownership

TL;DR: Use born-digital text extraction when your B2B SaaS team owns the PDF templates; preserve the extractor's page boundary and index only redact…

Nodejs PDF Chapter Split: Validated Ranges for Game Contract Signing

TL;DR: Treat a parsed table of contents as untrusted evidence, convert its chapter starts into half-open page intervals, validate the entire interva…

How to properly redact a PDF so the text is actually gone

Drawing a black rectangle over sensitive text in a PDF does not redact it. I need you to understand this before anything else, because people get fi…