Catch oversized media before WhatsApp rejects it

Media failures on WhatsApp are sneaky because they rarely fail at send time. The API accepts your request, returns a message ID, and everything looks healthy — then the message quietly lands as “failed” on your webhook minutes later, or arrives with a broken media placeholder. In a one-off test you notice. In a broadcast to ten thousand customers you may not, and the first signal is a support ticket or a dip in reply rates. An oversized hero image can silently sink an otherwise well-built campaign, and because delivery already “succeeded” from your app's point of view, retries and alerts often never trigger. The fix is boring but effective: validate every asset against the limits before it goes anywhere near the upload endpoint.

For images, bigger is not better. Phones render WhatsApp images inside a chat bubble a few hundred pixels wide, so a 4,000-pixel photo straight off a camera buys you nothing except a slower download and a higher chance of tripping the 5 MB cap. A practical target is 1,080 to 1,600 px on the longest edge, exported as JPEG at around 80 quality. That combination typically lands well under 1 MB, looks sharp on every device, and loads quickly even on congested mobile networks. Reserve PNG for graphics with hard edges and flat colour — screenshots, charts, logos on plain backgrounds — and remember that transparency is flattened in image messages anyway.

Documents deserve the same discipline, even with the generous 100 MB ceiling. A large share of WhatsApp users are on metered or slow connections, and a 40 MB brochure that takes minutes to download is a brochure that never gets read. Export catalogues and price lists with images downsampled to 100-150 DPI, strip embedded fonts you do not need, and aim for single-digit megabytes. If a document genuinely needs to be huge, consider sending a short summary PDF in chat and linking to the full version instead.

• Images — 1,080-1,600 px longest edge, JPEG at ~80 quality, comfortably under 5 MB.
• Videos — MP4 with H.264 video and AAC audio at 720p keeps typical clips under the 16 MB cap.
• Documents — target single-digit megabytes so they open fast on slow connections.
• Stickers — WebP at exactly 512 x 512 px, 500 KB static or 100 KB animated.

Bake these checks into your content workflow — ideally before assets reach whoever presses send — and media failures stop being a class of incident you have to debug at all.