Format comparisons
Each comparison puts the formats side by side on the criteria that matter for uploads, sharing and storage, then tells you which to pick for common situations.
- JPG vs PNG vs WebP vs HEICCompare JPG, PNG, WebP and HEIC on size, quality, transparency, browser and portal support, and pick the right one for uploads, websites, screenshots or photos.
- MP4 vs MOV vs WebMMP4, MOV and WebM compared on codecs, compatibility, file size and where each is accepted, with a decision list for WhatsApp, email, websites and iPhone video.
- MP3 vs AAC vs Opus vs WAVMP3, AAC, Opus and WAV compared on quality per bitrate, file size, compatibility and typical uses, with a decision list for voice notes, music and archiving.
- PDF vs JPG for document uploadsWhen to upload a scanned document as PDF and when as JPG: multi-page files, size limits, text search and portal rules, with a decision list for visas and jobs.
- Lossy vs lossless image compressionHow lossy and lossless image compression differ, how much each saves, when quality suffers, and which to use for photos, screenshots, logos and portal uploads.
- JSON vs CSV vs XMLJSON, CSV and XML compared on structure, size, readability, tooling and typical uses, with guidance on spreadsheet exports, APIs and document exchange.
Quick answers
The short version of each comparison: the situations people ask about most, and the format to pick. Open a comparison for the full criteria table and the reasons.
JPG vs PNG vs WebP vs HEIC
- Uploading a photo to a visa, ID, job or exam portal: JPG. Accepted everywhere; keep quality at 85% or higher and compress to the KB limit if there is one.
- Sharing a screenshot, logo or diagram with text: PNG. Lossless edges and transparency; JPEG artefacts make text fuzzy.
- Serving images on your own website: WebP. A quarter to a third smaller than JPEG, transparency and animation, supported by all current browsers.
- Storing photos on an iPhone or Mac: HEIC. Half the size of JPEG with better colour depth; convert only when you need to send a file elsewhere.
- Emailing photos to someone on Windows or Android: JPG. HEIC may not open without extra codecs; JPEG always does.
MP4 vs MOV vs WebM
- Sending video on WhatsApp, Telegram or email: MP4. H.264 in MP4 plays on every phone; compress under the app's size limit first.
- Uploading to a job, government or university portal: MP4. The only container every portal lists; MOV and WebM are frequently rejected.
- Editing footage from an iPhone or a camera in Final Cut or Premiere: MOV. Keep the original container and codec until the final export; convert only the export.
- Hosting video on your own website: WebM. Smaller files and royalty-free playback in most browsers; add an MP4 fallback for Safari and iOS.
- Archiving a finished video for the long term: MP4. The most widely readable container; H.264 or HEVC at a high bitrate.
MP3 vs AAC vs Opus vs WAV
- Sending an audio file to someone or uploading it to a portal: MP3. Plays on every device and is accepted by every form; 128 to 192 kbit/s is enough for voice and most music.
- Keeping the soundtrack of a video (MP4): AAC. The standard audio codec inside MP4 and MOV; better than MP3 at the same size.
- Voice notes, calls, podcasts where bandwidth matters: Opus. Clear speech at 16 to 32 kbit/s and the lowest latency of any codec.
- Recording, editing or mastering audio: WAV. No generation loss; convert to a lossy format only for the final delivery copy.
- Music library on Apple devices: AAC. Native to iTunes and Apple Music at 256 kbit/s; plays everywhere modern.
PDF vs JPG for document uploads
- Uploading a multi-page document (statement, contract, transcript): PDF. One file, pages in order, readable text if OCR was applied.
- Uploading a passport photo or a signature: JPG. Portals check pixels and KB; image tools hit both exactly.
- Uploading a single ID card or certificate where both are accepted: JPG. Easier to compress under the limit and always previews; switch to PDF if the form says "documents as PDF".
- The form limit is very tight (under 200 KB) for a document page: JPG. An image compressor reaches the target; PDF compression is less predictable.
- Sending a form you signed and want to keep intact: PDF. Harder to alter, keeps the page size, prints correctly.
Lossy vs lossless image compression
- Uploading a photo with a KB limit: Lossy. Only lossy compression can bring a photo under 200 KB without shrinking it to a thumbnail.
- Saving a screenshot, diagram or logo: Lossless. Sharp edges and text stay crisp, and the file is small anyway because the image has few colours.
- Archiving originals you may edit again: Lossless. Every lossy re-save loses a little more; keep a lossless (or original camera) master.
- Serving photos on a website: Lossy. Page weight matters and nobody can see the difference at 80 to 85% quality.
JSON vs CSV vs XML
- Exporting data for someone to open in Excel or Google Sheets: CSV. Opens directly, smallest file, no tooling needed.
- Building or consuming a web API or a config file: JSON. Native types, nesting, and parsers built into every language and browser.
- Exchanging documents with a system that publishes an XSD schema (e-invoicing, SOAP, publishing): XML. Validation, namespaces and signatures the standard depends on.
- Storing settings that people will edit by hand and comment: XML. Comments are allowed; alternatively use YAML or TOML rather than plain JSON.
- Bulk-loading millions of rows into a database: CSV. Streams line by line and is the format every loader accepts.