Free SMS Spam Checker
Carriers filter millions of texts every day without telling senders why. Paste your message below. It runs a carrier pattern scan and an AI model trained on real SMS spam data.
SMS Isn’t Email
Email spam filters scan content and sender reputation. SMS carriers watch something different. A real person texting from their own phone is treated very differently from a business sending 50,000 messages through a shortcode.
Three signals matter most:
Those three signals determine whether your message looks like a real conversation or a broadcast. Message content is just one part of the picture.
What Gets Your Texts Blocked?
Why Getting Replies Matters
Most SMS guides focus on content. But carriers also track how often people write back. A steady stream of replies tells carriers this is a real conversation, not a blast.
That’s why QuickText routes replies to your personal phone, not a dashboard. When someone replies, you respond naturally. The ratio stays healthy.
SMS spam words to avoid*
* well, sort of. Carriers don’t ban individual words. They read the whole message, and a single flagged phrase in a real conversation rarely causes a problem.
Both messages below use the word “free”:
Same word. One reads like a personal text. The other reads like a mass blast.
GSM-7 vs Unicode: The Hidden SMS Cost
Add one emoji to your message and the character limit drops from 160 to 70. That’s not a bug. It’s how SMS encoding works.
SMS has two encoding formats. Standard text uses GSM-7 (160 chars per SMS). The moment you include an emoji, a smart quote, or an em dash, it switches to Unicode, which cuts the limit to 70 characters per SMS.
| Encoding | Limit per SMS | Triggered by |
|---|---|---|
| GSM-7 (Standard) | 160 chars | Default for standard Latin characters |
| Unicode (UCS-2) | 70 chars | Any emoji, smart quote, em dash, ellipsis, or non-standard character |
When a message exceeds the limit it splits into multiple parts. Each part carries a small linking header, so the usable characters per part drop slightly: 153 for GSM-7, 67 for Unicode.
A simple example
You write a 140-character message with no special characters. That’s 1 SMS. You add a thumbs up at the end. Now it’s 140 Unicode characters. At 70 characters per SMS, that’s 3 parts instead of one.
What triggers the switch?
- Emoji of any kind
- Smart quotes (“ ” ‘ ’): common when copying from Word or Google Docs
- The em dash (—) and the ellipsis (…)
- Accented characters outside the standard Latin alphabet (e.g. é, ñ, ü, ø)
Personal Phone vs. Business Platform
There are two ways to send bulk SMS. Carriers treat them completely differently.
- Messages send from your actual phone
- Uses your personal mobile number
- Looks like a regular text to carriers
- Replies land in your messaging app
- No platform registration required
- Treated as personal conversation traffic
- Messages route through a commercial platform
- Uses a shortcode or 10DLC number
- Requires formal carrier registration
- Replies go to a web dashboard
- Mandatory STOP footer in every message
- Per-message fees apply
QuickText is P2P: your actual phone sends the messages. The CTIA defines P2P as low volume (roughly 15 messages/minute), under 1,000 per day, and bidirectional. Because the messages come from a real phone, carriers treat them like personal texts.
5 Ways to Improve SMS Deliverability
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1Personalize every message Use the recipient’s name at minimum. Even one first-name field changes how the message reads to a carrier’s pattern-detection system.
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2Vary your wording between sends Sending the exact same message to 500 people looks like a broadcast. Change your opener, swap a phrase, reorder a sentence. Carriers see variation as a sign of individual conversations, not a bulk blast.
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3Use a conversational tone Ask a question at the end. Messages that get replies prove to carriers that a real conversation is happening. Think of each text as the opening line of a conversation, not a broadcast.
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4Never use URL shorteners bit.ly and similar services are among the highest-risk elements in any SMS message. Use your full domain URL instead.
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5Pace your sends Firing 500 messages in 60 seconds looks automated no matter how personal the content. Spread sends over several hours and introduce random gaps between messages. That’s what a real person texting looks like.
How Many Texts Per Day Is Too Many?
A perfectly written message can still get flagged if it arrives in a burst of 500 sends in five minutes. Volume and pace matter as much as content.
What the guidelines say
The CTIA’s messaging guidelines put personal-phone traffic at roughly 15 messages per minute and under 1,000 per day. Go past those numbers and carriers start questioning whether the “personal” phone is really personal.
Real-world sweet spot: 100–400 per day
In practice, most people who stay off carrier radar send between 100 and 400 messages per day, spread across morning and afternoon.
Why random delays matter
If every message sends exactly 30 seconds apart, the pattern is machine-perfect. No human texts that way. A random gap between sends (45 seconds to 3 minutes) breaks the mechanical rhythm. The send log looks like a real person picking up their phone, not a scheduled broadcast.
Split sends across the day
150 in the morning, 150 in the afternoon. Early replies land before your second batch goes out, and your reply ratio stays healthy all day.
Is Texting Contacts Legal?
Short answer: it depends on how you got the number and how you’re sending.
US texting law centers on the TCPA (Telephone Consumer Protection Act), which was written mainly to stop robocalls and mass automated blasting. Its application to manual, personal-phone texting is more nuanced, and courts are still working it out.
The rough rule of thumb
- Purchased lists carry real legal risk regardless of the platform. This is where TCPA enforcement tends to focus.
- Warm contacts (people who gave you their number or have an existing relationship with you) are generally much lower risk.
- Texting from your own phone is treated differently than sending through a business SMS platform, but it doesn’t exempt you from everything.
QuickText is built for warm outreach and real conversations, not cold blasting. But the legal responsibility is yours. If you’re unsure, check with an attorney or the FCC’s guide on unwanted texts.
Common questions
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