Guides
The answers behind the tools
46 guides and comparisons. Why a file is the size it is, which format to pick, and what a conversion actually costs you. Each one ends at the tool that does the job, and every claim is one we can stand behind.
Images
20 guidesFormats, file sizes and what a photo gives away.
- Guide · Images
What is a HEIC file, and how do you open one?
HEIC is the format iPhones save photos in. What it is, why Windows and Android struggle with it, and the three ways to open or convert one without uploading it. - Guide · Images
Why are iPhone photos so big?
A modern iPhone photo can be 5 MB or more. Where the megabytes go — resolution, HDR, Live Photos, ProRAW — and how to get one small enough to send. - Guide · Images
What your photos quietly tell people
Every photo carries hidden data: where it was taken, on what, when, and sometimes who is in it. What EXIF holds, who can read it, and how to strip it before sharing. - Guide · Images
How to turn off the Gemini watermark — and what stays
How to turn off the visible Gemini watermark in Settings, where it stays on anyway, and what stays in the file: the invisible SynthID mark and AI metadata. - Guide · Images
JPG vs JPEG: what’s the difference?
JPG and JPEG are the same image format with two spellings of the extension. Why both exist, whether renaming is safe, and what to do when a form refuses one. - Guide · Images
Lossy vs lossless, in practice
Lossy formats discard detail to save space; lossless ones keep everything. What the difference means in practice for images, video and audio, and when each is right. - Guide · Images
Which image format belongs on your website?
JPG, PNG, WebP, AVIF and SVG compared for web use: what each is genuinely best at, what it costs in file size, and a simple rule for choosing. - Guide · Images
DPI vs pixels: what a photo size really means
A form asks for 300 DPI, a printer for 2 × 2 inches, a portal for 600 × 600 pixels. Which number decides the quality, and how to give each one what it wants. - Guide · Images
Blur, pixelate or black out: what really hides it
Pixelated text has been recovered, blurred faces matched and cropped screenshots restored. What each way of hiding leaves behind, and the one that leaves nothing. - Guide · Images
Transparent backgrounds, explained
Which image formats keep a transparent background, why a JPG fills it with white, and how to spot a “transparent” PNG with the checkerboard painted in. - Guide · Images
How to compress an image under 200 KB without losing quality
Get a photo under 200 KB, or 100, 50 or 20 KB, and keep it sharp: what to reduce first, which format to save as, and the mistakes that get uploads rejected.
Which format should you use?
- Format comparison
PNG vs JPG: which should you use?
Use JPG for photographs and PNG for everything with sharp edges: screenshots, logos, diagrams and text. PNG never loses detail but makes photos several times larger; JPG keeps photos small but smudges lines and can’t be transparent. - Format comparison
WEBP vs PNG: which should you use?
For images on a website, WebP does everything PNG does, transparency included, in a noticeably smaller file. PNG is still the safer choice for files you send to other people or open in older software. - Format comparison
WEBP vs JPG: which should you use?
WebP makes photos about a quarter to a third smaller than JPG at the same visible quality, and every current browser shows it. JPG remains the format every upload form, printer and email client accepts without question. - Format comparison
AVIF vs WEBP: which should you use?
AVIF usually produces the smallest file of any image format at the same quality, especially for photos, but it is slower to encode and slightly less widely supported. WebP is the practical middle ground: small, fast and supported everywhere modern. - Format comparison
HEIC vs JPG: which should you use?
HEIC stores iPhone photos in about half the space of JPG with the same quality, which is why Apple uses it. The catch is compatibility: Windows, Android apps and most upload forms still expect JPG, so convert when a photo leaves your Apple devices. - Format comparison
SVG vs PNG: which should you use?
SVG is drawn from shapes, so logos and icons stay razor sharp at any size in a tiny file. PNG is a grid of pixels that works for any picture, including photos and screenshots, and opens in every app. - Format comparison
TIFF vs PNG: which should you use?
Both are lossless. TIFF is built for print, scanning and professional photo work — 16-bit color, CMYK, layers and many pages in one file. PNG is built for screens: every browser and app opens it, it keeps transparency, and it is usually smaller for screenshots and graphics. - Format comparison
AVIF vs JPG: which should you use?
AVIF makes photos much smaller than JPG at the same visible quality and handles HDR and transparency, and every current browser shows it. JPG remains the format every upload form, printer, email client and photo app accepts, so use AVIF on your own site and JPG everywhere else. - Format comparison
GIF vs WEBP: which should you use?
Animated WebP does everything a GIF does in a fraction of the size, with full color instead of GIF’s 256 and smooth transparency. GIF’s advantage is reach: it animates in email, in old apps and in chat tools that still show a WebP as a still or refuse it.
Video
15 guidesContainers, codecs, and why clips are the size they are.
- Guide · Video
Container vs codec
MP4, MKV and MOV are boxes. H.264, HEVC and AV1 are what is inside. Why the difference explains almost every video file that refuses to play. - Guide · Video
H.264 vs H.265 vs AV1
The three codecs that matter, compared on file size, compatibility, encoding speed and licensing — and a straight answer about which to choose. - Guide · Video
Why is my video file so big?
Four numbers decide a video’s size: resolution, frame rate, bitrate and length. What each one costs, and which to change first when a file has to get smaller. - Guide · Video
How to compress a video without wrecking it
What actually costs quality when you shrink a video, what is free, and the order to change settings so a file gets smaller without looking it. - Guide · Video
How to play an MKV on an iPhone
iOS will not open MKV in the Photos or Files player. The two ways round it — a player app, or converting to MP4 — and which to choose. - Guide · Video
GIF vs MP4: why GIFs are so big
GIFs are huge because the format is from 1987 and has no motion compression. Why the same clip as an MP4 is a tenth the size, and when a GIF is still right. - Guide · Video
Video aspect ratios, and which one to use
Which shape of video each place expects, what happens when you post the wrong one, and the three ways to turn a landscape clip into a vertical one. - Guide · Video
Frame rate explained: 24, 30 or 60 fps
What frames per second changes in a video, why 60 fps files are bigger, why slow motion needs 120 fps, and when converting the frame rate helps. - Guide · Video
How to compress a video without uploading it
Shrink or convert a private video on your own device instead of a cloud server: how in-browser compression works, how to check nothing is sent, and its limits.
Which format should you use?
- Format comparison
MP4 vs MOV: which should you use?
MP4 and MOV usually contain exactly the same video, so quality isn’t the difference. MP4 plays on everything and is what websites and apps expect; MOV is Apple’s format, best kept for editing in Final Cut or iMovie. - Format comparison
MP4 vs MKV: which should you use?
MKV can hold almost anything, including several audio languages and subtitle tracks, which makes it ideal for a media library. MP4 holds less but plays on phones, browsers, editors and social apps, so it wins whenever a video is shared. - Format comparison
MP4 vs WEBM: which should you use?
WebM is the open format made for the web, and VP9 or AV1 inside it can be smaller than H.264 in MP4. MP4 is still the more compatible choice: it plays on iPhones, TVs and in every editor and social app. - Format comparison
AVI vs MP4: which should you use?
AVI is a 1990s container that usually holds older, less efficient codecs, so the same video is often much larger and won’t play on phones or in browsers. Convert AVI to MP4 unless an old device or program specifically needs AVI. - Format comparison
MKV vs AVI: which should you use?
MKV is the modern choice: it holds any codec, several audio tracks, subtitles and chapters, and handles HD video properly. AVI dates from 1992 and is tied to older codecs like DivX and Xvid, so the only reason to keep one is an old DVD player or TV that reads nothing else. - Format comparison
WMV vs MP4: which should you use?
WMV is Microsoft’s older format: it plays in Windows Media Player but struggles on Macs, iPhones, Android and the web. MP4 plays everywhere, from phones to smart TVs to every browser, usually in a smaller file, so convert WMV to MP4 whenever it leaves an old Windows PC.
Audio
11 guidesLoudness, bitrate, and what to publish in.
- Guide · Audio
What LUFS is, and the number to aim for
LUFS measures loudness the way ears hear it, not the way a peak meter does. What the standard targets are, and why normalizing beats turning the volume up. - Guide · Audio
What format should a podcast be?
What to record in, what to edit in, and what to publish: formats, bitrates, mono versus stereo and loudness, with the reasoning for each. - Guide · Audio
Bitrate and sample rate, explained
What bitrate and sample rate actually control, which one matters for file size, and why 320 kbps and 96 kHz are usually not worth what they cost. - Guide · Audio
How to convert files offline, in your browser
A web converter can keep working with no internet. How to set one up while online, install it as an app, test it in airplane mode, and what clears it again.
Which format should you use?
- Format comparison
MP3 vs WAV: which should you use?
WAV is uncompressed, perfect audio about ten times the size of an MP3. MP3 at 192 kbps or more sounds the same to almost everyone, so use it for listening and sharing, and WAV for recording, editing and mastering. - Format comparison
M4A vs MP3: which should you use?
M4A (AAC audio) sounds a little better than MP3 at the same bitrate and is the default for iPhones and iTunes. MP3 is older and slightly less efficient, but every car stereo, speaker and player ever made can play it. - Format comparison
FLAC vs MP3: which should you use?
FLAC is lossless: it keeps CD quality in roughly half the space of WAV. MP3 throws detail away to be about a fifth of FLAC’s size. Keep FLAC as your archive and convert to MP3 for phones, cars and sharing. - Format comparison
FLAC vs WAV: which should you use?
FLAC and WAV sound identical, bit for bit. FLAC is compressed without loss to about half the size and carries proper tags and artwork; WAV is uncompressed and opens in every audio editor. - Format comparison
OGG vs MP3: which should you use?
Ogg Vorbis is an open format that sounds a little better than MP3 at the same bitrate and is common in games and on Android. MP3 plays on far more devices, so it is the safer choice for anything you share. - Format comparison
OPUS vs MP3: which should you use?
Opus sounds better than MP3 at the same size, and far better at the low bitrates used for voice: it is what WhatsApp voice notes, Discord and video calls use. MP3 is still the format every car stereo, old player and DJ program opens without question. - Format comparison
AIFF vs WAV: which should you use?
AIFF and WAV hold exactly the same uncompressed audio, so they sound identical and are about the same size. AIFF is Apple’s and keeps song tags neatly in Music and Logic; WAV is the Windows and broadcast standard that every program on every system opens.