Custom Emoji Export Guide: Discord, Slack, and Telegram

Emoji, stickers, and animated media do not share one universal file specification. This guide was checked against the official sources below on October 17, 2026. It separates documented requirements from practical advice; we have not tested uploads to third-party workspaces or servers.

Verified requirements at a glance

The figures above describe the linked product documentation or Forgemoji’s current output. For Discord, check the current server uploader. For any platform, confirm the latest requirements before uploading because app features and workspace permissions can change.

Discord: check the current server uploader

Discord’s Emoji Resource reference documents emoji objects and management endpoints. It is not a universal user-facing upload specification for every server. Check the current server interface for accepted formats, file-size limits, permissions, and animation support instead of treating a commonly repeated pixel size as an official rule.

• •Check the current server uploader and your permission to add emoji.
• •Preview the design at the small size where it will appear in chat.
• •Use a clear silhouette and inspect transparent edges on light and dark backgrounds.
• •Keep a static PNG source even if the destination accepts an animated file.

Slack: square image, 128 KB or less

Slack’s Help Center recommends a square image with a transparent background and a file size of 128 KB or less. It lists JPG, PNG, and GIF formats, and says GIFs can contain up to 50 frames. The guidance does not set a pixel width or height, so do not present 128×128 px as a Slack requirement.

A format that appears in a message is not necessarily accepted by the custom emoji uploader. Check workspace permissions and test the actual upload flow with a copy of the file. Keep the original source so you can resize or convert it again.

Telegram: custom emoji and stickers are not the same

Telegram’s official guide gives different specifications for static custom emoji and static stickers. Custom emoji images must be exactly 100×100 px and use PNG or WebP. For static stickers, one side must be exactly 512 px and the other side can be 512 px or less; PNG and WebP are supported. Animated stickers and emoji use separate TGS or WEBM requirements.

• •Static custom emoji: exactly 100×100 px, PNG or WebP.
• •Static sticker: one side exactly 512 px and the other no greater than 512 px, PNG or WebP.
• •Animated TGS and video WEBM workflows have their own frame, duration, and file-size rules.
• •Forgemoji’s GIF/WebP animation export is not automatically a Telegram emoji or sticker file.

Keep one source and make destination copies

Forgemoji’s static download is a transparent 256×256 PNG, with seven preset animations exportable as GIF or WebP. Treat these as general-purpose source files, not a promise that every platform will accept them unchanged. Preserve the original and create a correctly sized and formatted copy for each destination.

Pre-upload checklist

1. 1.Confirm whether you are uploading custom emoji, a sticker, or a pasted image.
2. 2.Check the destination’s current official format, dimension, and file-size requirements.
3. 3.Use the specified canvas; do not assume every sticker or emoji must be square.
4. 4.Preview the transparent file against light and dark backgrounds.
5. 5.Test the actual uploader with a copy of the file.
6. 6.Keep the source PNG and a static fallback next to any animated export.

These are documented requirements and workflow checks, not a cross-platform upload test. Use the official sources below, verify the current destination settings, and keep an adaptable source file so you can make another export without regenerating the artwork.

Emoji Platform Size FAQ

Is 128×128 the universal custom emoji size?

No. Slack’s Help Center recommends a square image but does not specify pixel dimensions; Telegram static custom emoji must be 100×100 px, while static stickers use a 512 px side. Check Discord’s current server uploader for its requirements.

Can I upload the same WebP everywhere?

Do not assume so. Slack lists JPG, PNG, and GIF for custom emoji; Telegram accepts PNG or WebP for static emoji and stickers. Check Discord’s current uploader and keep a transparent PNG source.

Why do I need a static fallback?

Some platforms or workspaces use a static image in places where animation is unavailable, and some animated upload workflows require a separate fallback. Keeping one avoids a broken or missing picker preview.

Should I resize the source before uploading?

Keep the original and create a destination-specific copy. Telegram static custom emoji use 100×100 px, and sticker dimensions differ; Slack’s cited guidance specifies a square image and file-size limit but not pixel dimensions.