ToolHQ Blog
Guides, tutorials, and tips for getting the most out of free online tools. 185 articles.
185 articles — page 7 of 8
HEIC Is Technically Better Than JPG. Here Is Why You Still Need to Convert.
HEIC stores images at half the size of JPG with better quality. The problem is compatibility. Here is exactly when HEIC works and when converting to JPG is necessary.
A Meter Is Defined by the Speed of Light. An Inch Is Defined by a Meter. The Loop Took 200 Years to Close.
The meter traces back to the speed of light. The inch traces back to the meter. Here is the 200-year story of how two competing measurement systems got entangled.
Benjamin Franklin Left Two Cities Money in 1790. They Got It in 1991.
In 1790 Franklin left 1,000 pounds to Boston and Philadelphia and said wait 200 years. By 1991 it was $20 million each. Here's the math behind how.
41% of Successful Logins Involve a Compromised Password. Here Is How Attackers Use Them.
Cloudflare found that 41% of successful logins involve compromised credentials. Here is how credential stuffing works and how to check without exposing your password.
Fritz Lang Invented the Countdown for a 1929 Film. NASA Used It for Real Rockets.
The rocket launch countdown was invented for dramatic effect in a 1929 silent film. Here is how a filmmaker's device became a universal operational protocol.
Twitter's 140-Character Limit Was Set by SMS Arithmetic in 2006. Here Is What Character Limits Actually Measure.
Twitter chose 140 characters because SMS allows 160 and they needed 20 for a username. Here is what character limits actually measure and why Unicode complicates the count.
There Were 144 Time Zones in North America Before November 18, 1883. Here Is Why Railroads Fixed What Governments Wouldn't.
Before 1883, North America had 144 local time zones. The railroads resolved this in one day without waiting for government action. Here is how it happened.
Email Was Built for Text Only. Base64 Is the 1992 Workaround That Still Runs Email Attachments Today.
Email was designed for 7-bit ASCII text. Base64, invented in 1992 as part of MIME, lets binary files travel through text-only systems. Here is how it works.
A Video File Has Two Tracks. Converting to MP3 Keeps One.
Video files store audio and video as separate independent tracks. Here is how container formats work and why extracting audio keeps 95 percent of the content in 5 percent of the space.
Images Are 60 Percent of the Average Web Page. Here Is Which JPEG Quality Setting You Should Be Using.
Images carry over 60% of a typical web page's byte weight. Here is what JPEG quality settings actually control and what research says about the right setting for web use.
Your Phone Takes JPEGs. Your Accountant Needs PDFs. Here Is the Gap.
Why freelancers and independent contractors convert JPG photos to PDF for tax records, administrative submissions, and document filing workflows.
At 11:59:60 PM, Servers Around the World Panicked. The Single Extra Second That Crashed Reddit in 2012.
On July 1, 2012, a leap second in UTC caused a Linux kernel bug that took down Reddit, Mozilla, LinkedIn, and airline reservation systems for hours.
50% Off Plus 30% Off Is Not 80% Off. Here Is the Math Retailers Count On You Missing.
Sequential percentage discounts compound rather than add. A 50% sale plus a 30% coupon gives 65% off, not 80%. Here's the math behind stacked discounts and anchor pricing.
The Committee That Built an Unkillable Format: JPEG's 36-Year Run
JPEG was designed in 1986 by a committee from IBM, AT&T, and Canon. Here's the math, the patent wars, and why nothing has replaced it in 36 years.
The White Box Problem: What PNG Transparency Becomes in a JPG
Why converting a PNG with transparency to JPG creates a white box, and what to do instead. Covers JPEG's YCbCr model, alpha channels, and format tradeoffs.
She Recorded 18 Podcast Interviews as MP4. She Never Needed the Video.
Recording software captures video even when you only need audio. Here is why converting MP4 to MP3 cuts file size by over 90 percent with no loss to the audience.
URL Shorteners Were Built for Newsgroups. Twitter Nearly Killed Them. Then Twitter Made Them Indispensable.
TinyURL launched in 2002 to fix broken newsgroup URLs. Twitter's 140-character limit in 2009 made shorteners essential. Bitly links hit 2.1 billion clicks in November 2009.
The 300 DPI Rule Is Right for the Wrong Reasons
Most people misunderstand DPI in digital images. Here's what resolution actually means, how to calculate the pixels you need for print, and why the DPI number is just metadata.
Amazon Requires Pure White Backgrounds for Product Photos. Here Is What Enforcing That Standard Actually Costs Small Sellers.
Amazon mandates pure white (RGB 255,255,255) backgrounds for product photos or listings get suppressed. Here is how AI background removal changes the economics.
127 Pages from Four Different Sources, Merged Before Midnight
What PDF merging actually does technically, why the quality of mergers varies, and the real-world scenarios where assembling a single clean PDF is non-negotiable.
The Lawyer Sent the Contract as DOCX. Opposing Counsel Could Read Every Deleted Clause.
Word documents carry tracked changes, author names, and revision history that are invisible in the document but accessible in the file. Converting to PDF removes all of it.
Why the United States Still Uses Fahrenheit: A Scale Set by One Man's Body Temperature in 1724
Daniel Fahrenheit calibrated his scale against brine and body heat in 1714. Three centuries later, the US still uses it. Here is why switching proved impossible.
The Internet Ran Out of Addresses on February 3, 2011. Nobody Noticed Because of a Workaround Invented in 1994.
IPv4 addresses ran out in 2011. Network Address Translation has been hiding this from most users since 1994. The history of IP address exhaustion and what it means for your IP address.
QR Codes Are Not Just Fancy Barcodes. Here Is How They Actually Work.
QR codes use finder patterns, Reed-Solomon error correction, and mask patterns to encode thousands of characters readably from any angle. Here's how the system works.