Free creator tool
Diff Checker
Paste two versions and see exactly what moved, side by side or inline.
Updating…
Paste into either side to see what changed
Nothing is uploaded — the comparison runs in this tab.
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Postonus Pro
Loved this tool? Stop copying and pasting to schedule.
Connect 14+ channels (including Bluesky, Threads, and Reddit) in one dashboard. Schedule your content once, let Postonus auto-repurpose it native to every network.
No card until you publish.
Why people use it
- Compares anything you can paste — a rewritten caption, a JSON payload, a pricing table, a contract clause — with syntax highlighting for sixteen languages and plain text for everything else.
- Highlights the changed words inside a changed line, so a one-word edit does not read as a whole rewritten paragraph.
- Ignores indentation and trailing spaces on request, which is usually the difference between three real changes and four hundred noisy ones.
Suggested flow
- 01
Paste both versions
Drop the earlier version on the left and the newer one on the right. The comparison updates as you type — there is no button to press.
- 02
Pick how you read it
Side by side to see the two versions in parallel, inline to read the change as one stream. Set the language to get syntax colours.
- 03
Take the result with you
Copy a unified patch that git apply understands, or just read the count of added and removed lines.
About this tool
A diff checker that runs in your browser and never uploads what you paste
Compare two versions of text, code, JSON, YAML, Markdown, or a config file and see every added, removed, and changed line — side by side or inline, with syntax highlighting and word-level highlights inside each changed line. Nothing is sent to a server: the comparison happens in this tab, so a draft, a credential file, or an unpublished contract stays on your machine.
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Frequently asked questions Everything the first evaluation usually needs.
- What if I'm already on Buffer / Pallyy / Publer?
Keep them. Run Postonus side-by-side for 30 days. Put your 3 best posts into a Growth Workflow. If it isn't earning its keep, cancel us — not them.
- Does the AI write my posts?
No. You write the post. Postonus's AI re-fits your draft into each platform's native shape — character limits, tone, hashtag norms. You review every variant before it publishes. Voice profile keeps it sounding like you.
- Which platforms do you support?
Fourteen: Instagram, TikTok, YouTube, LinkedIn, Facebook, X, Threads, Pinterest, Bluesky, Reddit, Telegram, Discord, Google Business Profile, and Tumblr. WhatsApp Groups support is in beta.
- How does the free workspace and the 14-day trial work?
Sign up with no card and you get a free workspace: up to 3 connected channels, unlimited writing, and dated drafts on the calendar. Scheduling and publishing need a card. Adding one starts a 14-day trial on the plan you pick — nothing is charged until day 15, and your drafts are already there waiting.
- Can I import from another tool?
Yes. Bulk CSV import handles up to 50 posts per file (multiple files OK). Direct-from-Buffer import is on the Q4 roadmap.
- What happens if a post fails to publish?
Workers retry with exponential backoff. Failures show up in the Activity Feed with one-click retry. We email you only for unrecoverable failures (e.g. revoked token).