guides & field notes
The cutting room
Practical writing on splitting files well: platform specs that actually matter, workflows that hold up, and honest explanations of what happens under the blade.
pdf halves · October 25, 2026 · 6 min
How to Split Scanned PDF Pages in Half (and What a CropBox Really Does)
Turn two-page scans, A3 sheets and 2-up printouts into single pages without losing quality. How PDF page boxes work, the /Rotate trap that makes tools cut the wrong way, and the privacy catch of cropping.
pdf by size · October 25, 2026 · 5 min
Split a PDF by File Size: Why the Parts Never Add Up (and the 37% Email Tax)
Why dividing a PDF evenly misses size limits, how shared fonts, images and incremental saves change part sizes, and how to split a PDF into parts guaranteed to fit 10, 20 or 25 MB.
file · October 25, 2026 · 7 min
How File Splitting Really Works: .001 Parts, FAT32's 4 GB Wall, and Rejoining Without Software
A file engineer's guide to byte-splitting: why .001 parts can't open on their own, the exact FAT32 limit, the copy /b trap on Windows, CRC-32 vs SHA-256, and when RAR or ZIP volumes are the better tool.
csv · October 25, 2026 · 8 min
How to Split a Large CSV File Without Breaking It: Quotes, Encodings and Excel's Row Limit
Why line-based splitters corrupt CSVs, how quoted line breaks, BOMs and CRLF actually work at the byte level, and how to split a huge CSV into Excel-sized files with the header in every part.
field notes · July 20, 2026 · 2 min
Why Client-Side File Processing Is the Only Real 'Secure Upload'
Upload-based file tools ask for trust; local tools remove the need for it. What actually happens to uploaded files, and how to verify a tool processes locally.
video · July 16, 2026 · 2 min
How to Cut a Long Video into Short Clips for Social Media
Turn webinars, lectures, and streams into short-form clips in your browser. Finding clip-worthy moments, marking in/out points, and batch exporting.
image · July 14, 2026 · 2 min
How to Split an Image into a 3×3 Grid for Instagram (Free, No Upload)
Step-by-step guide to slicing one photo into nine tiles for a seamless Instagram grid — with exact pixel sizes, posting order, and common mistakes to avoid.
pdf · July 8, 2026 · 2 min
How to Split a PDF Without Uploading It Anywhere
Split contracts, bank statements, and medical records into separate PDFs entirely in your browser. Why local processing matters and how to verify a tool is actually private.
audio · July 1, 2026 · 2 min
How to Split One Audio File into Separate Tracks
Cut a long recording — a concert, DJ set, rehearsal, or tape rip — into individual tracks in your browser. Marker placement, silence detection, and export tips.
image · June 30, 2026 · 2 min
Instagram Grid & Post Dimensions in 2026: The Complete Size Guide
Every Instagram image size that matters in 2026 — feed posts, the 3:4 profile grid, carousels, Reels covers — and how they affect split-photo grids.
pdf · June 24, 2026 · 2 min
How to Extract Specific Pages from a PDF (3 Methods Compared)
Pull exact pages out of any PDF: visual selection, range syntax, or print-to-PDF. When to use each method and how to keep the output at original quality.
image · June 18, 2026 · 2 min
How to Make a Seamless Instagram Carousel from One Wide Photo
Turn a panorama or wide design into a swipeable, edge-to-edge Instagram carousel. Sizing formula, slicing steps, and design rules that make the seam invisible.
video · June 12, 2026 · 2 min
The Ideal Video Clip Length for Every Platform (2026 Data)
Maximum lengths and realistic sweet spots for TikTok, Reels, Shorts, X, and LinkedIn video in 2026 — and why completion rate beats duration.
pdf by size · June 10, 2026 · 3 min
PDF Too Big to Email? Attachment Limits and How to Split Around Them
Gmail, Outlook, and iCloud attachment limits in one table — and how to split a large PDF into email-sized parts in your browser, free.
audio · June 5, 2026 · 2 min
Remove Silence from Audio Recordings: A Practical Guide
Strip dead air from podcasts, interviews, and voice memos. How silence detection works, what threshold and duration mean, and when not to cut.
pdf · May 28, 2026 · 2 min
PDF Page Ranges Explained: Syntax, Examples, and Real-World Recipes
Master range syntax like 1-3, 5, 8-10 for splitting PDFs. Includes recipes for contracts, scanned books, invoices, and double-sided scans.
image · May 21, 2026 · 2 min
How to Slice a Sprite Sheet into Individual Images
Cut game sprite sheets, icon sets, and UI mockups into separate PNG files in the browser. Covers grid math, transparent backgrounds, and batch export.
pdf · May 14, 2026 · 2 min
LinkedIn Carousels Are Secretly PDFs: The Complete 2026 Guide
LinkedIn document posts are just PDFs — one page per slide. Sizing, page counts, design rules, and how to split or assemble carousel PDFs in your browser.
video · May 7, 2026 · 2 min
Lossless vs Re-Encoded Video Cutting: What's Actually Happening
Why some video cuts are instant and perfect while others re-encode: keyframes, GOPs, and codecs explained — and which trade-off fits which job.
audio · April 28, 2026 · 2 min
How to Split a Podcast Episode into Chapters (and Why You Should)
Turn a long podcast recording into chaptered segments: where to cut, how to keep a timestamp list for show notes, and exporting clips for social.
pdf · April 16, 2026 · 3 min
Shrink a PDF by Splitting It: When Cutting Beats Compressing
Compression degrades scans and re-renders documents. Learn when splitting a PDF into parts is the smarter way to hit size limits — and how to estimate part sizes.
audio · April 9, 2026 · 2 min
WAV vs MP3: Which Format Should Your Audio Exports Use?
Why split.tools exports WAV, what that costs in file size, when MP3 is the right final format, and how to avoid stacking generation loss.
video · March 25, 2026 · 2 min
A Streamer's Highlight Workflow: From 4-Hour VOD to Posted Clips
A repeatable system for turning stream VODs into highlight clips: marking moments live, batch-cutting after the stream, and versioning for each platform.
field notes · March 12, 2026 · 4 min
The Browser APIs Behind split.tools: How In-Tab File Splitting Works
A technical tour of the web platform features that make serverless file splitting possible: File API, Blob.slice, canvas, pdf-lib, Web Audio, MediaRecorder, and a streaming client-side ZIP writer.