Find the limit, then prepare a copy
- Read the complete error and current help. Check the upload surface: chat attachments, profile images, documents and video thumbnails can have different rules.
- Inspect actual file size, width, height and format. Keep the original separately. Compare the byte limit, minimum dimensions and required aspect ratio.
- Export an accepted format in an image editor; renaming an extension does not convert it. Resize excess pixels while preserving required dimensions; crop only when the destination needs a different shape.
- Compress the copy with the Bitinz image compressor, then download and inspect it. Bitinz has no target-size setting and does not resize images; compare the actual output with the destination's limit.
- Upload the downloaded file. If it meets the published requirements but still fails, check the account, attachment route and service error before reducing quality again.
The upload route changes the rule
These official rules were checked on 2026-10-28. Use the rule shown for your account and device if it differs; limits and upload interfaces can change.
| Destination | What the official rule says | What to do |
|---|---|---|
| Discord free attachments | The newer attachment FAQ states 20 MB for non-Nitro accounts, checked before compression. Some accounts are in upload-limit experiments. | Prepare a smaller file before attaching it; do not rely on Discord's later compression to pass the initial check. |
| WhatsApp photos or documents | HD gives clearer photos than Standard; it is not a promise of the original file. Documents can be sent without compression, up to 2 GB. | Use the photo route for viewing in chat, or attach a document when preserving the original file matters. |
| YouTube video thumbnails | JPG or PNG; under 2 MB when uploading on mobile, or under 50 MB on desktop. Recommended 3840 × 2160, minimum width 640 pixels and recommended 16:9 aspect ratio. | Check the upload device and keep thumbnail text readable. Custom thumbnails also require an eligible, verified account. |
The YouTube row covers video thumbnails; Shorts and podcasts have separate rules. For Instagram, check help for your upload screen instead of assuming a universal ceiling. Email and marketplace rules are covered separately in image size requirements.
If a smaller image still will not upload
Choose compatibility before chasing a smaller number. A destination can accept JPG but reject WebP, even if WebP is lighter; see which image format to use. Preserve transparency when it matters, and choose a background deliberately before exporting a transparent graphic as JPG.
For a strict small limit, follow the resize-and-check workflow in how to compress an image under 100 KB. If compression barely changes a file, the large-after-compression guide explains the next useful adjustment.
Teams preparing recurring uploads can use the developer API with an account and monthly quota. The receiving service still decides whether each image meets its own rules; a successful compression does not grant upload permission.
Check the file you are about to send
- The chosen attachment type matches the task, and the account can use it.
- The downloaded file fits the actual size limit and uses an accepted format.
- Pixel dimensions and aspect ratio meet the destination's requirements.
- Fine text, faces, edges and transparency still look right at the intended viewing size.
- The file selected for upload is the new copy, and it opens correctly on your device.
FAQ
- Why is my image rejected even though its file size is small enough?
- The destination may also restrict image dimensions, aspect ratio, file format or account access. Read the complete error and check the rule for that specific upload screen.
- What is Discord's free file upload limit?
- Discord's newer attachment FAQ states 20 MB for non-Nitro accounts, checked before compression. Discord also tests different allowances, so follow the limit shown for your account.
- Does sending an HD photo on WhatsApp preserve the original file?
- HD offers clearer photo sharing than Standard, but should not be treated as original-file delivery. Send the image as a document when the original file matters, within WhatsApp's 2 GB document limit.
- Does every YouTube thumbnail have to be under 2 MB?
- No. YouTube's current video-thumbnail limit is under 2 MB for mobile uploads and under 50 MB for desktop uploads. Other thumbnail types have their own rules, and file size is separate from account eligibility.
Tools in this guide
- Compress imagesMake JPG, PNG and WebP files smaller in their own format, in batches and for free.Compress images
- JPG to WebPTurn photos into WebP and compare the size with the original.Convert JPG
- PNG to WebPConvert graphics to WebP and keep their transparency.Convert PNG
- Image compression APICompress images from a script or a build pipeline, with a free monthly quota.Read the API docs
Sources
Figures checked against the official pages on October 28, 2026. Platforms change their rules, so check the linked page before relying on a limit.