Sync files, screenshots and inline images between Jira and Slack
Screenshots are where triage actually happens — the stack trace, the broken UI, the log snippet. Threadmaker syncs file attachments both ways between a Jira comment and its Slack thread, and renders images inline in the Jira comment body so reviewers see them without opening a separate tab.
Add Threadmaker to Slack — free for up to 10 Jira users.
How attachment sync works
- Slack → Jira: files attached to a Slack reply land as attachments on the matching Jira comment.
- Jira → Slack: files attached to a Jira comment arrive as separate file-share messages in the Slack thread, paired with the parent comment.
Inline images
Attach an image — PNG, JPEG, JPG, GIF, or WebP — to a Jira comment and it renders inline in the comment body, not just in the Attachments tab. SVG and other formats aren't inlined for security reasons, but still appear as regular attachments.
The limit: 5 files × 2 MB per comment
Threadmaker forwards file bytes through the Cloudflare Workers and Atlassian Forge proxies, which have fixed body-size budgets — so each comment carries up to 5 files of 2 MB each. Files over the cap are dropped on the Slack→Jira side with an ephemeral warning to the uploader explaining what happened. It's best-effort: a failed file upload never aborts the comment, so the text still syncs. For large files (videos, log dumps, full database exports), upload to your team's storage and paste a link in the comment instead.
FAQ
Do attachments sync when I edit a message? Yes — adding a file while editing a synced message or comment propagates, within the same 5 × 2 MB cap. Removing a file does not retract the copy already synced to the other side; delete the whole message or comment to retract it.
What happens to a file over 2 MB? On the Slack→Jira path it's dropped and the uploader gets an ephemeral heads-up. On the Jira→Slack path an oversize attachment simply doesn't appear in Slack — there's no warning on that side. Either way the comment text still syncs; only the oversize file is left behind.
Can I sync a whole folder or a video? No — the proxy budgets are sized for triage artifacts (screenshots, log snippets, small PDFs and CSVs). Link out to your storage for anything larger.
Related
Full reference in the setup guide. See also edits and deletes, @-mention mapping, and live status in the thread — or read the engineering-triage playbook, which leans on inline screenshots. Back to all features.
Ready to try it?